Verify whether the statement is true.

[maxtheminawes]

Homework Statement

2cos^2 4x-1=0

a)x= pi/16 x=3pi/16

Homework Equations

The Attempt at a Solution

a) x=pi/16

u=cosx
v=4x
2u^2 v-1=0
i'm stuck here

 

[jedishrfu]

are you solving this equation: 2 * cos^2(4x) - 1 = 0

first plugin the x=pi/16 --> 4x = pi/4 and so you have 2 * cos^2(pi/4) - 1 = 0

so what is cos(pi/4)? then square it and solve.

 

[Mark44]

Homework Statement

2cos^2 4x-1=0

What does this mean? I can think of at least two interpretations. Use parentheses to make the meaning clear.

a)x= pi/16 x=3pi/16

Homework Equations

The Attempt at a Solution

a) x=pi/16

u=cosx
v=4x
2u^2 v-1=0
i'm stuck here