Question

fast please can you answer it​

Answer 1

Step-by-step explanation:

cos²A+tan²-1/sin A =tan²A

apply both sides with +1

cos²A+Tan²A-1+1/SinA=Tan²A+1.

we knew that 1+tan²A=Sec²A.

cos²A+Tan²A/SinA=sec²A. (Tan²=sin²A/cos²A)

cos²A+sin²A/cos²/sinA=1/cos²A

cos⁴A+sin²A/cos²A/SinA=1/cos²A

Cos⁴A+sin²A/cos²SinA=1/cos²A

cos⁴A+Sin²A=cos²AsinA/cos²A

cos⁴A+sin²A=SinA

cos⁴A=sinA-sin²A

cos²A=sinA/cos²A. —Sin²A/cos²A

cos²A=sinA/cosA .1/cosA – tan²A

cos²A=tanAsecA-tan²A

1/sec²=tanAsecA –tan²A

1=tanAsec²A–tan²ASec²A

1=sec²A(tanA-tan²A)

cos²A=sin/cos-sin²A/cos²A

cos²A=SinAcosA-sin²A/cos²A