Question

Please Help Me

Answer 1

Am I right?

Answer 2

\[(a+b)(a-b)=a^{2}-b^{2}\]

Answer 3

first one right

Answer 4

for the last one use thu property that @amorfide wrote

Answer 5

the*

Answer 6

the first one is correct.
The second one should be
-sinx
and third one should be (cotx)^2

Answer 7

Why would it be cotx though?

Answer 8

* (cotx)^2

Answer 9

part two comes out as
\[\frac{ \csc^{2}x-1 }{ sinx }\]
\[\sin^{2}x+\cos^{2}x=1\] using this identity if we divide by sin^2x
\[1+\cot^{2}x=\csc^{2}x\]

\[\frac{ 1+\cot^{2}x-1 }{ sinx }\]

we know that cot^2x is cos^2x/sin^2x

\[\frac{ \cos^{2}x }{ \sin^{2}x } \times \frac{ 1 }{ sinx }\]

Answer 10

you can finish that

Answer 11

Ok, thanks for the help

Answer 12

using the identity you can figure out yourself why the last one should be cot^2x

Answer 13

Bravo!
All the best @ohohaye