Question

cos(2arcsin x) write as an algebraic expression of x

Answer 1

did you see my answer to the last one?

Answer 2

i did

Answer 3

this is a completely different question though

Answer 4

for this one you need
\[\cos(2\theta)=1-2\sin^2(x)\]

Answer 5

oops make that
\[\cos(2\theta)=1-2\sin^2(\theta)\]

Answer 6

replace \(\theta\) by \(\arcsin(x)\) and you are done in one step pretty much

Answer 7

let me know if that is not clear, i can write it out

Answer 8

alright ill see how i do with that. thanks ^.^

Answer 9

yw

Answer 10

yes, that is the first step
but what is
\[\sin(\arcsin(x))\]?

Answer 11

x

Answer 12

but sin is squared?

Answer 13

ok
then it should be clear if you understand \[\sin^2(\arcsin(x))\] means
\[(\sin(\arcsin(x))^2\]

Answer 14

1-2x^2

Answer 15

youre awesome!!! thank you soo much!!! <3

Answer 16

aahhh i thought that might be the confusion
\[\sin^2(\theta)\] means \((\sin(\theta))^2\) yes you have it

Answer 17

yupp i got it right!

Answer 18

yay
yw

Answer 19

thanks to your help! goodnight

Answer 20

gnight