Question

Can anyone show me how to factor the expression 3sin^2x-5sinx-2 ?
The answer is (3sinx+1)(sinx-2) according to my text, but how?

Answer 1

Spit the middle term in two parts such that their sum is '-5 sinx' & their product is \(-6sin^2x\).

Answer 2

\[\large\rm 3(\color{orangered}{\sin x})^2-5\color{orangered}{\sin x}-2\]If you think of it like a normal polynomial it might make more sense to you,\[\large\rm 3\color{orangered}{y}^2-5\color{orangered}{y}-2\]Do you remember how to factor something like this?

Answer 3

Oh yes, I guess I was getting tripped up by the way it looked

Answer 4

Thank you