Question

Find all solutions to the equation.

7 sin2x - 14 sin x + 2 = -5

Answer 1

this is a quadratic equation

\[7\sin^2(x) - 14\sin(x) + 7 = 0\]

which can simplify to

\[7(\sin^2(x) - 2\sin(x) + 1) = 0\]

the quadratic can be factorised and is a perfect square.

so that should make it easier to find the solution.

Answer 2

I'm really stuck on this question can you elaborate more? :))

Answer 3

well make a simple substitution

let sin(x) = u

so your problem is

\[7(u^2 -2u +1) = 0\]

all you need to do is factor the quadratic in the brackets...

Answer 4

So i get (u-1)(u-1)

Answer 5

I'm really confused please help