If sin ( A+B) =1 and sin ( A-B )=1/2 then find value of tan (A+2B) and...
Solution:
Given: sin ( A B) =1 and sin ( A-B )=1/2
We are supposed to find the value of tan (A 2B) and tan (2A B).
Approach: We will use the trigonometric formulae to solve the problem.
Trigonometric Formulae:
sin (A+B) = sin A cos B + cos A sin B
sin (A-B) = sin A cos B - cos A sin B
tan (A+B) = (tan A + tan B) / (1 - tan A tan B)
tan (A-B) = (tan A - tan B) / (1 + tan A tan B)
Calculation:
Finding value of sin A and sin B:
sin (A+B) = sin A cos B + cos A sin B
Put A = B in the above equation to get:
sin (2A) = 2 sin A cos A
=> sin A = (1/2)
Similarly, using sin (A-B) = sin A cos B - cos A sin B and putting A = 2B and B = A/2, we get:
sin (3B / 2) = (sqrt(3) / 2) sin B
=> sin B = (sqrt(3) / 3)
Finding value of cos A and cos B:
Using sin^2 A + cos^2 A = 1, we get:
cos A = (sqrt(3) / 2)
Similarly, using sin^2 B + cos^2 B = 1, we get:
cos B = (1/2)
Finding value of tan (A 2B) and tan (2A B):
Using the formula, tan (A+B) = (tan A + tan B) / (1 - tan A tan B), we get:
tan (A + 2B) = (tan A + tan 2B) / (1 - tan A tan 2B)
=> tan (A 2B) = (2sqrt(3)) / 3
Similarly, using the formula, tan (A-B) = (tan A - tan B) / (1 + tan A tan B), we get:
tan (A - B) = (tan A - tan 2B) / (1 + tan A tan 2B)
=> tan (2A B) = (sqrt(3)) / 3
Answer:
The value of tan (A 2B) is (2sqrt(3)) / 3 and the value of tan (2A B) is (sqrt(3)) / 3.
If sin ( A+B) =1 and sin ( A-B )=1/2 then find value of tan (A+2B) and...