Question

Solve cos (x) (cos x +1) = 0
I dont even know where to start here honestly

Answer 1

@campbell_st can you help me? please

Answer 2

ok... so this is a quadratic function

if wrote it as x(x + 1) = 0

could you solve it..?

Answer 3

Yes I can so basically just distribute and then retricelike terms and solve?

Answer 4

but the basics are that the equation is already factored... so if either factor is zero, the who equation is zero...

so you need to solve

cos(x) = 0

and cos(x) + 1 = 0

those angles will be the solutions...

Answer 5

So cos x = -1 then I just find where this is true on the unit cirlce and use the cooresponding radians right?

Answer 6

but then i only get pi as an answer

Answer 7

oh but when it equals zero is important to so
pi and 3pi/2 and pi/2

Answer 8

yes use the unit circle, but I find the curve y = cos(x) a little easier



I don't know if you need to answer in radians or degrees

hope it helps