dux 3,142 Posted November 6, 2017 Share Posted November 6, 2017 how to integrate this: f(x) = sec(x)[ 8tan(x) - 5sec(x) ] ? Link to comment Share on other sites More sharing options...
kyulkyung 5,023 Posted November 6, 2017 Share Posted November 6, 2017 o god i forgot all my calc Link to comment Share on other sites More sharing options...
ricecake 730 Posted November 6, 2017 Share Posted November 6, 2017 multiply it out f(x)=8secxtanx - 5sec2x pull out the constants integrate (secxtanx --> secx; sec2x --> tanx) edit: so the answer should be 8secx - 5tanx + c i believe Link to comment Share on other sites More sharing options...
Stepkdramafan226 6,734 Posted November 6, 2017 Share Posted November 6, 2017 https://www.wolframalpha.com/input/?i=f(x)+%3D+sec(x)%5B+8tan(x)+-+5sec(x)+%5D https://www.wolframalpha.com/input/?i=integrate+f(x)+%3D+sec(x)%5B+8tan(x)+-+5sec(x)+%5D Forgot about calculus when I didn't need it anymore. Not sure if that helps tbh Link to comment Share on other sites More sharing options...
Swirl900 2,201 Posted November 6, 2017 Share Posted November 6, 2017 Take the integral:integral sec(x) (8 tan(x) - 5 sec(x)) dxExpanding the integrand sec(x) (8 tan(x) - 5 sec(x)) gives 8 tan(x) sec(x) - 5 sec^2(x):= integral(8 tan(x) sec(x) - 5 sec^2(x)) dxIntegrate the sum term by term and factor out constants:= 8 integral tan(x) sec(x) dx - 5 integral sec^2(x) dxRewrite tan(x) sec(x) as (sin(x))/(cos^2(x)):= 8 integral(sin(x))/(cos^2(x)) dx - 5 integral sec^2(x) dxFor the integrand (sin(x))/(cos^2(x)), substitute u = cos(x) and du = -sin(x) dx:= 8 integral-1/u^2 du - 5 integral sec^2(x) dxFactor out constants:= -8 integral1/u^2 du - 5 integral sec^2(x) dxThe integral of 1/u^2 is -1/u:= 8/u - 5 integral sec^2(x) dxThe integral of sec^2(x) is tan(x):= 8/u - 5 tan(x) + constantSubstitute back for u = cos(x):Answer: || = 8 sec(x) - 5 tan(x) + constant I copied that from wolfram ^^^ Link to comment Share on other sites More sharing options...
Izara 15,657 Posted November 6, 2017 Share Posted November 6, 2017 Problem: ∫sec(x)(8tan(x)−5sec(x))dx∫secâ¡(x)(8tanâ¡(x)−5secâ¡(x))dx Expand: =∫(8sec(x)tan(x)−5sec2(x))dx=∫(8secâ¡(x)tanâ¡(x)−5sec2â¡(x))dx Apply linearity: =8∫sec(x)tan(x)dx−5∫sec2(x)dx=8∫secâ¡(x)tanâ¡(x)dx−5∫sec2â¡(x)dx Now solving: ∫sec(x)tan(x)dx∫secâ¡(x)tanâ¡(x)dx This is a standard integral: =sec(x)=secâ¡(x) Now solving: ∫sec2(x)dx∫sec2â¡(x)dx This is a standard integral: =tan(x)=tanâ¡(x) Plug in solved integrals: 8∫sec(x)tan(x)dx−5∫sec2(x)dx8∫secâ¡(x)tanâ¡(x)dx−5∫sec2â¡(x)dx =8sec(x)−5tan(x)=8secâ¡(x)−5tanâ¡(x) The problem is solved: ∫sec(x)(8tan(x)−5sec(x))dx∫secâ¡(x)(8tanâ¡(x)−5secâ¡(x))dx =8sec(x)−5tan(x)+C=8secâ¡(x)−5tanâ¡(x)+C ANTIDERIVATIVE COMPUTED BY MAXIMA: ∫f(x)dx=F(x)=∫f(x)dx=F(x)= 8cos(x)−5tan(x)+C8cosâ¡(x)−5tanâ¡(x)+C No further simplification found! Link to comment Share on other sites More sharing options...
Pleasure 2,956 Posted November 6, 2017 Share Posted November 6, 2017 f(x) = pink bible there u go boo <3 Link to comment Share on other sites More sharing options...
dux 3,142 Posted November 6, 2017 Author Share Posted November 6, 2017 multiply it out f(x)=8secxtanx - 5sec2x pull out the constants integrate (secxtanx --> secx; sec2x --> tanx) edit: so the answer should be 8secx - 5tanx + c i believe Take the integral: integral sec(x) (8 tan(x) - 5 sec(x)) dx Expanding the integrand sec(x) (8 tan(x) - 5 sec(x)) gives 8 tan(x) sec(x) - 5 sec^2(x): = integral(8 tan(x) sec(x) - 5 sec^2(x)) dx Integrate the sum term by term and factor out constants: = 8 integral tan(x) sec(x) dx - 5 integral sec^2(x) dx Rewrite tan(x) sec(x) as (sin(x))/(cos^2(x)): = 8 integral(sin(x))/(cos^2(x)) dx - 5 integral sec^2(x) dx For the integrand (sin(x))/(cos^2(x)), substitute u = cos(x) and du = -sin(x) dx: = 8 integral-1/u^2 du - 5 integral sec^2(x) dx Factor out constants: = -8 integral1/u^2 du - 5 integral sec^2(x) dx The integral of 1/u^2 is -1/u: = 8/u - 5 integral sec^2(x) dx The integral of sec^2(x) is tan(x): = 8/u - 5 tan(x) + constant Substitute back for u = cos(x): Answer: | | = 8 sec(x) - 5 tan(x) + constant I copied that from wolfram ^^^ Problem: ∫sec(x)(8tan(x)−5sec(x))dx∫secâ¡(x)(8tanâ¡(x)−5secâ¡(x))dx Expand: =∫(8sec(x)tan(x)−5sec2(x))dx=∫(8secâ¡(x)tanâ¡(x)−5sec2â¡(x))dx Apply linearity: =8∫sec(x)tan(x)dx−5∫sec2(x)dx=8∫secâ¡(x)tanâ¡(x)dx−5∫sec2â¡(x)dx Now solving: ∫sec(x)tan(x)dx∫secâ¡(x)tanâ¡(x)dx This is a standard integral: =sec(x)=secâ¡(x) Now solving: ∫sec2(x)dx∫sec2â¡(x)dx This is a standard integral: =tan(x)=tanâ¡(x) Plug in solved integrals: 8∫sec(x)tan(x)dx−5∫sec2(x)dx8∫secâ¡(x)tanâ¡(x)dx−5∫sec2â¡(x)dx =8sec(x)−5tan(x)=8secâ¡(x)−5tanâ¡(x) The problem is solved: ∫sec(x)(8tan(x)−5sec(x))dx∫secâ¡(x)(8tanâ¡(x)−5secâ¡(x))dx =8sec(x)−5tan(x)+C=8secâ¡(x)−5tanâ¡(x)+C ANTIDERIVATIVE COMPUTED BY MAXIMA: ∫f(x)dx=F(x)=∫f(x)dx=F(x)= 8cos(x)−5tan(x)+C8cosâ¡(x)−5tanâ¡(x)+C No further simplification found! thank you all so much! i idndt know wolfram did that! Link to comment Share on other sites More sharing options...
Izara 15,657 Posted November 6, 2017 Share Posted November 6, 2017 thank you all so much! i idndt know wolfram did that!Here you go..https://www.integral-calculator.com just put yr question that you wanna integrate and the calculator will show you step by step I had done my study in Calculus 3 years ago..so I can't really remembered it Link to comment Share on other sites More sharing options...
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