If lim x → − a x + a x 7 + a 7 = 7 , then the value of a is

lim x → − a a − ( − x ) a 7 − ( − x ) 7 = 7 ⇒ 7 a 6 = 7 ⇒ a 6 = 1 ∴ a = ± 1

Mathematics - Limits Question with Solution | TestHub

MathematicsLimitsGeneral ( Limit existence)Easy2 minQB

MathematicsEasymultiple choice

If $lim_{x \to - a} \frac{x ^{7} + a ^{7}}{x + a} = 7$ , then the value of $a$ is

Answer:

A,B

Solution:

$lim_{x \to - a} \frac{a ^{7} - ( - x ) ^{7}}{a - ( - x )} = 7 \Rightarrow 7 a^{6} = 7 \Rightarrow a^{6} = 1$

$∴ a = \pm 1$

Stream:JEESubject:MathematicsTopic:LimitsSubtopic:General ( Limit existence)

⏱ 2mℹ️ Source: QB

Loading discussions...