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This is an internet homework, and the answer does have +c in it. I have no idea how to do this since its asking for indefinite, but then it gives me from 0 to pi/4.... any ideas?

2007-11-16 08:52:31 · 4 answers · asked by Zach B 1 in Science & Mathematics Mathematics

4 answers

I get the answer 1/7.

I split the integral up like this:

tan^5x tan x sec^2x dx. We know that d/dx tan x is sec^2 x. By integration by susbstitution we get

u^5 * u du because u = tan x and d/du = sec^2 x.

then we integrate u^6 to get

1/7 u^7 = 1/7 tan^7x | from u = 0 and u = (pi/4)

then we evaluate to get 1/7

2007-11-16 09:07:28 · answer #1 · answered by Anonymous · 1 0

Been a at the same time as; combine with the aid of areas enable u=x^2-a million then du= (2x)dx resolve int (u^4)du from 0 to a million supplies (u^5)/5 then substititute back the u: that's [(x^2-a million)^5]/5 evaluated from 0 to a million: whilst x=a million the int is 0, whilst x=0 the int is -a million/5 -a million/5 - 0 = -a million/5 answer

2016-10-17 00:08:34 · answer #2 · answered by ? 4 · 0 0

this is a definite integral, so like you said, no constant c.

the easiest way to do this problem is substitution

u = tanx so du = sec^2(x)dx

change your limits of integration
if x = 0, then u = tan(0) = 0
if x = pi/4, then u = tan(pi/4) = 1

now the new integral is

integral from 0 to 1 of u^6du

= (1/7)u^7 with limits of int from 0 to 1

I hope that this helps

2007-11-16 09:13:41 · answer #3 · answered by Terry S 3 · 0 0

Evaluate the integral over the interval [0, π/4].

∫(tan^6 x)(sec²x)dx
Let
u = tan x
du = sec²x dx
____

= ∫u^6 du = (1/7)u^7 = (1/7)(tan x) | [Eval from 0 to π/4]

= (1/7)[tan(π/4) - tan(0)] = (1/7)(1 - 0) = 1/7

2007-11-16 09:20:22 · answer #4 · answered by Northstar 7 · 0 0

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