Question

Select the correct answer. Which of the following is a solution to 4sin2x − 1 = 0? A. 30° B. 60° C. 90° D. 120°

Answer 1

A. 30°

Explanation:

We have been given the equation

`4\sin^2x-1=0`

Add 1 to both sides

`4\sin^2x=1`

Divide both sides by 4

`\sin^2x=(1)/(4)`

Take square root both sides

`√(\sin^2x)=\sqrt{(1)/(4)}\\\\\sin x=\pm(1)/(2)\\\\x=30^(\circ)`

Thus, A is the correct option.

Answer 2

The correct option is A.

Explanation:

The correct form is:

4sin^2 x − 1 = 0

First step is add 1 to both sides:

4sin^2 x-1+1=0+1

4sin^2 x=1

Now to eliminate 4 divide both sides by 4

4sin^2 x/4=1/4

sin^2 x=1/4

Take square root at both sides

√sin^2 x = √1/4

sinx = 1/2

Thus the correct option is 30° ....