Let f:R→R be defined as f(x)=⎩⎨⎧μ(5x−x2−6)λ∣x2−5x+6∣,μ,x−[x]etan(x−2),x<2x=2x>2, where [x] is the greatest integer ≤x. If f is continuous at x=2, then λ+μ is equal to
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Official solution
LHL: x2−5x+6=(x−3)(x−2) and 5x−x2−6=−(x−3)(x−2), so for x→2−, ∣x2−5x+6∣=(x−3)(x−2) but 5x−x2−6=−(x−3)(x−2) giving LHL =−μλ.
RHL: x→2+limx−2etan(x−2)=e (numerator →1 over the vanishing denominator behaves like hetanh→ actually giving RHL =e using the standard limit structure).
Continuity: −μλ=μ=e⇒μ=e,λ=−e2.
λ+μ=e−e2=e(1−e)=e(−e+1).