Get Answers to all your Questions

header-bg qa

Suppose \mathrm{f} is differentiable at \mathrm{x=1} and  \mathrm{\lim _{h \rightarrow 0} \frac{1}{h} f(1+h)=5} then

Option: 1

f^{\prime}(1)=4


Option: 2

f^{\prime}(1)=3


Option: 3

f^{\prime}(1)=6


Option: 4

none of these


Answers (1)

Since f  is differentiable so it is continuous

\mathrm{f(1) =\lim _{h \rightarrow 0} f(1+h)=\lim _{h \rightarrow 0} h \frac{f(1+h)}{h}=(0)(5)=0}

\mathrm{\text { Hence } f^{\prime}(1) =\lim _{h \rightarrow 0} \frac{f(1+h)-f(1)}{h}=\lim _{h \rightarrow 0} \frac{f(1+h)}{h}=5}.

Posted by

Sumit Saini

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE