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Question: Answered & Verified by Expert
Let cosα+β=45 and let sinα-β=513, where 0α,βπ4, then tan2α=
MathematicsTrigonometric Ratios & IdentitiesBITSATBITSAT 2019
Options:
  • A 207
  • B 2516
  • C 5633
  • D 192
Solution:
2147 Upvotes Verified Answer
The correct answer is: 5633

0α,βπ4; α+βπ2

cos(α+β)=4/5tan(α+β)=3/4

sin(α-β)=5/13α-βθ1

and tan(α-β)=5/12

tan2α=tan(α+β+α-β)

=tan(α+β)+tan(α-β)1-tan(α+β)tan(α-β)

=3/4+5/121-3/4×512=5633

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