Question

Trig Identities

Answer 1

Do you know the identity for sin(2x)?

Answer 2

2sinxcosx

Answer 3

Right.... now, you have
\[\large h=\frac{ v^2 }{4.9 }\sin x \cos x\] and you want an answer in terms of sin(2x) right? So how about if you multiply the given equation by a factor of 2/2....\[\large h=\frac{ 2 }{ 2 }\frac{ v^2 }{4.9 }\sin x \cos x=\frac{ v^2 }{2(4.9) }2\sin x \cos x\]

See that?

Answer 4

then that becomes......?

Answer 5

\[(v^2\div2(4.9)) \sin2x ?\]

Answer 6

would the answer be B. \[275.92\sin(2\theta)\] then?

Answer 7

I believe it is B as well. What do you think, @DebbieG ?

Answer 8

Yes, I think it's B. :) Good job.