Question

Find all solutions to the equation.

2cos(theta) + sqrt 2 = 0

Answer 1

let's represent cos theta by x, can you find value of x?
\[2x+\sqrt 2=0\]

Answer 2

-√2/2

Answer 3

Good or it can be simplified as
\[\frac{-1}{\sqrt 2}\]

Answer 4

oh ok

Answer 5

We have now
\[\cos \theta=\frac{-1}{\sqrt 2}\]

Answer 6

do you know the value of theta if cos theta =1 /sqrt 2

Answer 7

mmm no

Answer 8

what's cos 45?

Answer 9

0.52532198881 ?

Answer 10

i just plugged that in my calculator :/

Answer 11

Hmmm, there might be another way than just calculator.

Answer 12

oh i see.

Answer 13

how to I write the answer in radians or in terms of pie?

Answer 14

It's gotta be half or a right angle to work.

Answer 15

A right angle in radians is \(2\pi / 4 = \pi / 2\). So what is half of that?

Answer 16

There are 4 right angles in a full revolution.

Answer 17

half of π/2? i don't know