NIMCET 2010 — Mathematics PYQ
NIMCET | Mathematics | 2010If sin−11+a22a−cos−11+b21−b2=tan−11−x22x then x is equal to:
Choose the correct answer:
- A.
a
- B.
b
- C.
1−aba+b
- D.
1+aba−b
1+aba−b
Explanation
Step 1: Substitute the identities into the given equation.
Substituting these into the original equation:
2tan−1a−2tan−1b=2tan−1x
Step 2: Simplify the equation by dividing by 2.
tan−1a−tan−1b=tan−1x
Step 3: Apply the subtraction formula for tan−1.
Using the formula tan−1A−tan−1B=tan−1(1+ABA−B):
tan−1(1+aba−b)=tan−1x
Step 4: Solve for x.
Comparing both sides, we get:
x=1+aba−b
Correct Option:
(d) 1+aba−b
Explanation
Step 1: Substitute the identities into the given equation.
Substituting these into the original equation:
2tan−1a−2tan−1b=2tan−1x
Step 2: Simplify the equation by dividing by 2.
tan−1a−tan−1b=tan−1x
Step 3: Apply the subtraction formula for tan−1.
Using the formula tan−1A−tan−1B=tan−1(1+ABA−B):
tan−1(1+aba−b)=tan−1x
Step 4: Solve for x.
Comparing both sides, we get:
x=1+aba−b
Correct Option:
(d) 1+aba−b
