Question

please prove this identity. tan +sec=1/sec*tan..

Answer 1

\[1/\sec=\cos,~~~so,\]\[tanx+secx=(cosx) \times tanx\]\[tanx+secx=cosx~tanx\]\[tanx=sinx/cosx~~~AND~~~secx=1/cosx~~~~So,\]\[\frac{Sinx}{Cosx}+\frac{1}{Cosx}=cosx \times \frac{Sinx}{Cosx}\]\[\frac{Sinx+1}{Cosx}=Sinx\]\[Sinx+1=SinxCosx\]\[\frac{Sinx}{Sinx}+\frac{1}{Sinx}=\frac{SinxCosx}{Sinx}\]\[1+Cscx=Cosx\]\[1=Cosx-Cscx\]

Answer 2

I think this is an open equation, it's not true or false, you would want to solve for x.

Answer 3

no, I mean how can I prove that the right side of the equation is equal to the left side using the fundamental identities

Answer 4

please help me.

Answer 5

change them to sin cos identities to see how to manipulate it easier

Answer 6

I already did that but still I'm confused.

Answer 7

please, if anyone knows this identity please hep me

Answer 8

lets make sure it is an identity first :)

http://www.wolframalpha.com/input/?i=tan%28x%29%2Bsec%28x%29%3D1%2F%28sec%28x%29tan%28x%29%29

so the issue is, that it is NOT an identity to start with; so no matter how much you try to manipulate it it will NEVER work out as an identity

Answer 9

we can solve for some specific values of x that will work out, but an identity has to work for ALL values of x.

Answer 10

so it means that the equation given was not qualified to be proved as equal identities?

Answer 11

correct

Answer 12

thank you so much

Answer 13

youre welcome