Question

Prove: cos θ - (cos θ)•(sin^2 θ) = cos3 θ. You must show all work.

Answer 1

@mathmale

Answer 2

The sine is squared but it's not letting me edit it.

Answer 3

@mathmale

Answer 4

sin^2 is always (1-cos^2)

Answer 5

its an identity

Answer 6

@Danyboii, would you be able to check if my math is correct?

Answer 7

You've done a very nice job (on paper). And Danny is right: this is a trig identity.

Answer 8

Awesome! Thank you both, so my work is correct?!

Answer 9

@mathmale & @danyboii ?

Answer 10

yes it is but you to prove it so go on and prove the equation :3

Answer 11

no wait

Answer 12

dude u have to prove it that its Cos^3 so u cant take anything on the right hand side

Answer 13

how about now?

Answer 14

can u write the initial equation properly pls cuz i got Cos^3

Answer 15

upload?

Answer 16

dude wait

Answer 17

yes i'm uploading the work proving what you just said. I understood that concept of replacing the sin^2 theta. please give me a second to upload it so you can tell if it's right.

Answer 18

okie :3

Answer 19

OK! :) How about now?! @danyboii

Answer 20

awesome Bro (y) perfect :3

Answer 21

yayyyy!!! <3 thank you so much for your help :) @danyboii

Answer 22

no problem :3

Answer 23

anytime :D