Question

Find all solutions to the equation.

7 sin2x - 14 sin x + 2 = -5

Answer 1

whoops sin^2x

Answer 2

medal and fan for whoever helps me

Answer 3

this one is easy - just put y=sinx and then solve y as a quadratic eqn.

Answer 4

could you please show me?

Answer 5

are you there?

Answer 6

y=sinx so y^2=sin^2x....then solve for y...

Answer 7

well you have a quadratic equation.

start by adding 5 to both sides of the equation and you get

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

now divide every term by 7

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

this can be factorised, its a perfect square

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

hope this helps.... you'll need to solve it from here...

Answer 8

okay that helps a lot thank you!

Answer 9

:)