Question
Question: In ∆ABC if 2∆ = a<sup>2</sup> – (b – c )<sup>2</sup> then value of tan A equals...
In ∆ABC if 2∆ = a2 – (b – c )2 then value of tan A equals
A
3–4
B
34
C
158
D
None
Answer
34
Explanation
Solution
Q 2∆ = (a – b + c) (a + b – c)
2∆ = 4 (s – b) (s – c)
2 = (s–b)(s–c)s(s–a)⇒ tan2A = 21
⇒ tanA = 1–412.21 = 34