Question

In Figure 5, ∆ABC is right angled at B, BC = 7 cm and AC − AB = 1 cm. Find the value of cos A − sin A.

Answer 1

It is given that is right angled at B, BC = 7 cm and AC − AB = 1 cm then we have to find the value of

The following diagram is given

AC − AB = 1…… (1)

Now, apply the Pythagoras theorem in, we get

Now add the equation (1) and (2), we get

Put the value of in equation (2), we have

Now,

Hence