Question

does tan^2x+sec^2x=1 for all values of x

Answer 1

\[\tan^2 x+ \sec^2 x =\frac{ \sin^2x }{ \cos^2 x}+\frac{ 1 }{ \cos^2 x} = \frac{ \sin^2 x+1 }{ \cos^2 x } \neq 1\]

Answer 2

thank you :)

Answer 3

Happy to help

Answer 4

No how can you be sure that another x value would make statement wrong ?

Answer 5

You need to prove for alll x values not for a particular x value

Answer 6

Oh ! I am sorry. I didn't really give attention to your solution.

Answer 7

So my solution is wrong or uncomplete ? What do you think ?

Answer 8

What if you cannot find a particular x value that makes the statement wrong even if the the statement not true for all x values?