Question

[Periodic Functions and Applications]

Solve sin^2x=1/4 for 0 12 years ago

Answer 1

From sin^2x=1/4
So sinx = 1/2
You could continue by looking up for formulas

Answer 2

Hmmm I got that far, then first solution is 30degrees, the second is 150degrees...? There must be something else I am missing, as the textbook lists two other values :S

Answer 3

\[\sin^2 x = 1/4 \implies \sin(x) = \pm 1/2\]

Answer 4

Remember that the square of \(-1/2\)

Answer 5

is also \(1/4.\)

Answer 6

Ah, so while 30 and 150 degrees are the solutions when sin is positive, having sin^2x means that I must also find solutions when sin is negative?

Answer 7

Indeed.

Answer 8

Okay, thanks for the help!

Answer 9

What did you get for the negative values?

And no problem!

Answer 10

210 and 330 degrees

Answer 11

That is correct.

Answer 12

YES