Question

in triangle ABC,angleB=90° and tanA=1 then show that 2sina.cosA=1

Answer 1

hope it will help you.....

Answer 2

B=90 means it is right angle triangle
tanA=1 means prendicular and base is1
and hypotenuse is √2 by Pythagoras theorem

sin=prepend÷hyp
cos=base÷hypo

2×1÷√2×1÷√2=1
2×(1÷√2)2=1
1=1
hence proved