4 4 votes Find $f(x)$ if $f'(x)=6x^2+\sec^2 x$ and $f(0)=4$.$f(x)=2x^3+\tan x+4$ $f(x)=2x^3-\tan x+4$ $f(x)=6x^3+\tan x+4$ $f(x)=2x^3+\tan x-4$ Calculus goclasses goclasses-cs-dpp goclasses-cs-dpp-day-285 goclasses-da-dpp goclasses-da-dpp-day-187 calculus-&-optimization goclasses-calculus-&-optimization-practice-questions integration + – GO Classes 412 views answer comment Share Follow Print See 1 comment 1 1 comment reply mogg commented Jun 1 reply Follow flag Logic is - integrate f'(x) we get {f(x)+c}, then from f(0) we get value c, after that put c in f(x) 0 0 replyShare Please log in or register to add a comment.
1 1 vote Since $f'(x)=6x^2+\sec^2 x$, integrate both sides.$$\Rightarrow f(x)=\int(6x^2+\sec^2 x)dx$$$$\Rightarrow f(x)=2x^3+\tan x+C$$Now use $f(0)=4$.$$\Rightarrow f(0)=2(0)^3+\tan0+C$$$$\Rightarrow 4=0+0+C$$$$\Rightarrow C=4$$$$\boxed{\therefore {f(x)=2x^3+\tan x+4}}$$Answer: A. GO Classes answered May 30 GO Classes comment Share Follow 0 reply Please log in or register to add a comment.