Question

Solve it toooo......​

Answer 1

tanA=ntanB

1/tanB=n/tanA

cotB=n/tanA -----------(1)

sinA=msinB

1/sinB=m/sinA

cosecB=m/sinA -------(2)

cosec²B-cot²B=1

m²/sin²A-n²/tan²A=1

m²/sin²A-n²/(sin²A/cos²A)=1

m²/sin²A-n²cos²A/sin²A=1

(m²-n²cos²A)/sin²A=1

m²-n²cos²A=sin²A

m²-n²cos²A=1-cos²A [∵, sin²A+cos²A=1]

-n²cos²A+cos²A=1-m²

-cos²A(n²-1)=-(m²-1)

cos²A=m²-1/n²-1 (Proved)

Answer 2

Answer:

your answer attached in the photo