Question

class 10th trigonometry question solution ​

Answer 1

Answer:

As angle C is 90°... Angle a +Angle b sum up to 90..

cos(a+b)=cos90°=0

Answer 2

Answer:

in the question we have right angled triangle at c and cos a+b so

AC hieght

CB base

AB hypotenuse

so cos a+b =c= 90⁰

we know that cos 90⁰ = 0

I hope this will help you