Answers

2014-09-17T10:18:57+05:30
2014-09-17T10:26:14+05:30
Cot A=cos A/sin A
by cross multiply
sin A cot A=cos A
cot A√1-cos ² A=cos A
squaring on both sides
cot²A(1-cos²A)=cos²A
cot²A-cot²A cos²A=cos²A
cot²A=cos²A+cot²A cos²A
cot²A=cos²A(1+cot²A)
cos²A=cot²A/1+cot²A
cosA=plus or minus√cot²A/1+cot²A
0