Question

Find all solutions of the equation in the interval [0, 2π) algebraically.

sin^2 x + cos x + 1 = 0

Answer 1

\[
\sin ^2 x=1-\cos ^2 x
\]

Answer 2

Let \(u=\cos x\)

Answer 3

what next...?

Answer 4

@wio

Answer 5

What did you get?

Answer 6

I don't know how to do it.

Answer 7

@wio

Answer 8

i got 0,π/2, k/π. Is that correct?!?

Answer 9

@ybarrap Do you understand how to solve this my friend?

Answer 10

What happens when \(x=\pi\)?

Answer 11

-1?

Answer 12

$$
\sin^2 \pi + \cos \pi + 1 = 0\\
\sin \pi = ?\\
\sin^2\pi=?\\
\cos \pi =?\\
$$

Answer 13

sinπ= 0

Answer 14

sin2π= 0 cosπ=-1

Answer 15

So is \(x=\pi\) the solution?

0-1+1=?

Answer 16

1. got it. thanks