Question

What are the x-coordinates for the maximum points in the function f(x)=4cos(2x-pi) from x=0 to x=2pi

Answer 1

Well isn't the range of y=cos(u) is [-1,1]
So the max value for y=cos(u) is 1
And the min value for y=cos(u) is -1
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So the max value for f(x)=4cos(u) is?

Answer 2

f(u)=4cos(u) *

Answer 3

I'm not quite sure if I follow

Answer 4

cos(u) has max value 1
so
4cos(u) has max value 4(1)=4

Answer 5

Does that make sense?

Answer 6

Yes

Answer 7

So the max value of 4cos(2x-pi) is 4(1)=4
so you need to solve 4cos(2x-pi)=4 to find for which x 4cos(2x-pi) is 4

Answer 8

Or basically solve cos(2x-pi)=1

Answer 9

x = pi/3

Answer 10

sorry x=pi/2

Answer 11

should be two values

Answer 12

And x=3pi/2?

Answer 13

yep

Answer 14

correct @Patsfan12 @freckles

Answer 15

Alright thanks guys!