Question

If cot (A+B) = 1/√3, cot (A-B) = √3 where A > B and 0° < A + B < 90°, then A and B respectively :
a) 60°, 30°
b) 60°, 15°
c) 45°, 30°
d) 45°, 15°

ALIGARH MUSLIM UNIVERSITY +2 ENTRANCE TEST PAPER 2012-13

Answer 1

HELLO DEAR,

cot(A+B)=1/√3

cot(A+B)=cot 60°

A+B= 60°------------(1)

cot (A-B)=√3

cot(A-B)=cot 30°

A - B = 30°-------------------(2)

from --(1) and--(2)

A+B=60
A - B = 30°
__________
2A=90°

A=90/2

A= 45° put in (1)

we get,

B=60-45

B=15°

hence ,

option (d) is correct



I HOPE ITS HELP YOU DEAR,
THANKS

Answer 2

Hello...
Here is your solution

Thank you so much...........

So the correct answer is option (D)............