Question

solve the following:
2cos^2(x)+5sin(x)+1=0

Answer 1

I can help. but what is your own idea beforehand @e.chado ?

Answer 2

I really don't know where to start on this one. I'm confused on how to start because its cos+sin

Answer 3

what if we can make use of a variable change? first write the equation all in terms of sin and then take sin to be simply x. what it now looks like to you?

Answer 4

it is like a quadratic equation. Okay?

Answer 5

2y^2+5x+1=0?

Answer 6

I would have to use different variables because cos(x) and sin(x) are different right?

Answer 7

no, try again. replace cos^2(x) with an appropriate equation. make the expression all in terms of just one trig function.

Answer 8

a hint more: