doubt

Question

In a triangle ABC,sinA.cosB=(1/4) and 3tanA=tanB,then the triangle is?

a) right angles

b)equilateral

c)none of these

Answer 1

3 tanA =tan B

3 sin A/cos A =sin B/cos B

3 sin A.cos B=cos A.sinB

cos A.sin B= 3/4    (becoz sin A.cos B=1/4 )

now sin(A+B) = sinA.cosB+cosA.sinB

sin(A+B)=1/4+3/4=1

ie A+B=90 digree

so C=90

so right angle triangle

Answer 2

Right angled triangle