Question

i will be a fan of who helps me with this:

Prove: sin θ - sin θ•cos2 θ = sin3 θ. You must show all work.

Answer 1

\(\normalsize\color{blue}{ \sin θ - \sin θ\times\cos^2 θ = \sin3 θ }\)

\(\normalsize\color{blue}{ \sin θ (1-\cos^2 θ )= \sin3 θ }\)

divide by sin (on both sides, and apply `sin²x+cos²x=1`

Answer 2

Tell me if you need more help

Answer 3

sinθ - sin θ•cos2 θ
sinθ(1-cos^2θ)
sinθ*sin^2θ =sin^3θ

Answer 4

awesome! i will and thanks :D both of you

Answer 5

Anytime

Answer 6

I was assuming, that it is \(\normalsize\color{blue}{ \sin θ (1-\cos^2 θ )= \sin^3 θ }\)

Answer 7

we can do \(\normalsize\color{blue}{ \sin θ (1-\cos(2θ)~~~ )= \sin(3θ) }\) if you need :)

Answer 8

And btw, \(\normalsize\color{blue}{ \sin θ (1-\cos(2θ)~~~ )= \sin(3θ) }\)

1) Click and hold ALT
2) click the number code (using the numbers that are on the right of the keyboard, not the ones below F1, F2, F3, etc., )
3) release the ALT

`0 1 8 5` ¹
`2 5 3` ²
`0 1 7 9` ³
`0 2 1 5` ×
`2 4 6` ÷
`7 5 4` ≥
`7 5 5 ` ≤
`2 4 1` or `7 5 3` ±
`2 4 7` ≈
`2 5 1` √

Answer 9

just some alt codes if you want... have a good day !

Answer 10

thanks :) you too!

Answer 11

Yw