Q40 of 42 Page 193

If cos x + sin x = √2 cos x then prove that cos x – sin x = √2 sin x.

Given that cos x + sin x = √2 cos x


∴ we can write:



Multiply both sides by √2 + 1


∴ we get,






Hence Proved.


More from this chapter

All 42 →
38

If m sin θ + r cos θ = p and m cos θ – n sin θ = q, then prove that m2 + n2 = p2 + q2.

 39

If 3 x = sec θ and find the value of .

 41

If 3 x = cosec θ and find value of .

 42

Express all the trigonometric ratios in terms of tan θ.