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Integration Help C4

Heres the question: Integrate (sec x)^2 (3tanx 4)

I got this far

(1 + (tan x)^2)(3tanx - 4)

{using the trig identity (sec x)^2 = 1 + (tan x)^2}

Mulitplied it out:

3tanx - 4 + 3(tanx)^3 - 4(tanx)^2 dx

Is this correct so far, and to integrate would i just let x=tanx and go from there?

Thanks in advance.
HUPextreme
Heres the question: Integrate (sec x)^2 (3tanx 4)

I got this far

(1 + (tan x)^2)(3tanx - 4)

{using the trig identity (sec x)^2 = 1 + (tan x)^2}

Mulitplied it out:

3tanx - 4 + 3(tanx)^3 - 4(tanx)^2 dx

Is this correct so far, and to integrate would i just let x=tanx and go from there?

Thanks in advance.

Integrate (sec x)^2 (3tanx 4)
Let u = tanx here.
du/dx = sec^2x => du = sec^2x.dx

=> Integrate (sec x)^2 (3tanx 4) dx
= Integrate (3u-4).du
= 3u^2/2 - 4u + c
= 1.5(tanx)^2 - 4tanx + c
Reply 2
oh cool, i didnt see that.

Thanks for the help, and for the swift reply.