Transcript Document

9.5 = Variation Functions
Direct Variation
Direct Variation – y varies directly as x
Direct Variation – y varies directly as x
y = kx
Direct Variation – y varies directly as x
y = kx
*Note: k = constant of variation (a #)
Direct Variation – y varies directly as x
y = kx
*Note: k = constant of variation (a #)
Inverse Variation
Direct Variation – y varies directly as x
y = kx
*Note: k = constant of variation (a #)
Inverse Variation – y varies inversely as x
Direct Variation – y varies directly as x
y = kx
*Note: k = constant of variation (a #)
Inverse Variation – y varies inversely as x
y=k
x
Direct Variation – y varies directly as x
y = kx
*Note: k = constant of variation (a #)
Inverse Variation – y varies inversely as x
y=k
x
Joint Variation
Direct Variation – y varies directly as x
y = kx
*Note: k = constant of variation (a #)
Inverse Variation – y varies inversely as x
y=k
x
Joint Variation – y varies jointly as x and z
Direct Variation – y varies directly as x
y = kx
*Note: k = constant of variation (a #)
Inverse Variation – y varies inversely as x
y=k
x
Joint Variation – y varies jointly as x and z
y = kxz
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
b = 20
a
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
b = 20 , inverse
a
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
b = 20 , inverse, k = 20
a
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
b = 20 , inverse, k = 20
a
b. y = -0.5
x
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
b = 20 , inverse, k = 20
a
b. y = -0.5
x
y = -0.5x
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
b = 20 , inverse, k = 20
a
b. y = -0.5
x
y = -0.5x , direct
Ex. 1 State whether each equation
represents a direct, joint, or inverse
variation. Then name the constant of
variation.
a. ab = 20
b = 20 , inverse, k = 20
a
b. y = -0.5
x
y = -0.5x , direct, k = -0.5
Ex. 1 State whether each equation represents a
direct, joint, or inverse variation. Then name the
constant of variation.
a. ab = 20
b = 20 , inverse, k = 20
a
b. y = -0.5
x
y = -0.5x , direct, k = -0.5
c. A = ½bh
Ex. 1 State whether each equation represents a
direct, joint, or inverse variation. Then name the
constant of variation.
a. ab = 20
b = 20 , inverse, k = 20
a
b. y = -0.5
x
y = -0.5x , direct, k = -0.5
c. A = ½bh , joint
Ex. 1 State whether each equation represents a
direct, joint, or inverse variation. Then name the
constant of variation.
a. ab = 20
b = 20 , inverse, k = 20
a
b. y = -0.5
x
y = -0.5x , direct, k = -0.5
c. A = ½bh , joint , k = ½
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
18 = k(15)
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
18 = k(15)
18 = 15k
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
18 = k(15)
18 = 15k
18 = k
15
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
18 = k(15)
18 = 15k
18 = k
15
6=k
5
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
2) y = kx
18 = k(15)
18 = 15k
18 = k
15
6=k
5
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
2) y = kx
18 = k(15)
y = 6x
18 = 15k
5
18 = k
15
6=k
5
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
2) y = kx
18 = k(15)
y = 6x
18 = 15k
5
18 = k
15
6=k
5
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
2) y = kx
18 = k(15)
y = 6x
18 = 15k
5
18 = k
y = 6(20)
15
5
6=k
5
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
2) y = kx
18 = k(15)
y = 6x
18 = 15k
5
18 = k
y = 6(20)
15
5
6=k
y = 120
5
5
Ex. 2 Find each value.
a. If y varies directly as x and y = 18
when x = 15, find y when x = 20.
1) y = kx
2) y = kx
18 = k(15)
y = 6x
18 = 15k
5
18 = k
y = 6(20)
15
5
6=k
y = 120
5
5
y = 24
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
1=k
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
1=k
2) y = kxz
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
1=k
2) y = kxz
y = 1xz
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
1=k
2) y = kxz
y = 1xz
y = 1(9)(-5)
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
1=k
c.
2) y = kxz
y = 1xz
y = 1(9)(-5)
y = -45
If y varies inversely as x and y = -14 when x =
12, find x when y = 21
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
1=k
c.
2) y = kxz
y = 1xz
y = 1(9)(-5)
y = -45
If y varies inversely as x and y = -14 when x =
12, find x when y = 21
1) y = k
x
-14 = k
12
-168 = k
b.
Suppose y varies jointly as x and z. Find y
when x = 9 and z = -5, if y = -90 when z = 15
and x = -6
1) y = kxz
-90 = -6(15)k
-90 = -90k
1=k
c.
2) y = kxz
y = 1xz
y = 1(9)(-5)
y = -45
If y varies inversely as x and y = -14 when x =
12, find x when y = 21
1) y = k
x
-14 = k
12
-168 = k
2) y = k
x
21 = -168
x
x = -8