RD Sharma - Mathematics

Book: RD Sharma - Mathematics

Chapter: 7. Values of Trigonometric Functions at Sum of Difference of Angles

Subject: - Class 11th

Q. No. 1 of Exercise 7.1

Listen NCERT Audio Books to boost your productivity and retention power by 2X.

1

If sinA = 4/5 And cosB = 5/13, where 0 <A, B < π/2, find the values of the following:

(i) sin(A +B)


(ii) cos(A +B)


(iii) sin(A –B)


(iv) cos(A -B)

Given sinA = 4/5 And cosB = 5/13


We know that where 0 <A,B < π/2






Then,


(i) Sin(A +B)


We know that sin(A +B) = sinA cosB + cosA sinB





(ii) Cos(A +B)


We know that cos(A +B) = cosA cosB - sinA sinB





(iii) Sin(A –B)


We know that sin(A -B) = sinA cosB - cosA sinB





(iv) Cos(A –B)


We know that cos(A -B) = cosA cosB + sinA sinB





Chapter Exercises

More Exercise Questions

6

If SinA = 1/2, cosB = , where π/2<A < π And 0 <B < π/2, find the following:

(i) tan(A +B)(ii) tan(A -B)