Monday

April 21, 2014

April 21, 2014

Posted by **david** on Thursday, April 5, 2007 at 1:33am.

f'(x)=(tanx-x*sec(x)^2)/(tanx)^2

That's the quotient rule for derivatives or as my teacher says:

Low,low, low D'High, minus High d'low all over low square that's the quotient rule. It's a song which helps. D'High or d'low means the derivative of the top or bottom.

Anyways: the answer choices are:

2,1/2,1+pi/2,pi/2-1, 1-pi/2

and i keep getting 1-pi/8. This question is from an AP test in 1985 so i don't think they made a mistake in these answers.

deriv = (1*tan x - x sec^2 x)/tan^2 x

so for x= pi/4

deriv = (1 - pi/4(2))/1

=1 - pi/2, which was one of the choices

**Related Questions**

Calculus - find the derivative of f(x)=tanx-4/secx I used the quotient rule and ...

Trigonometry - Given that a^2+b^2=2 and that (a/b)= tan(45degee+x), find a and b...

Trigo - Given that a^2+b^2=2 and that (a/b)= tan(45degee+x), find a and b in ...

Calculus - Integration - Hello! I really don't think I am understanding my calc ...

calculus - Did I do this problem right? Find the first and second derative-...

Pre-Cal - Perform the addition or subtraction. tanx - sec^2x/tanx tan^2(x)/tan(x...

Biology - 20. When the blood enters the gill filaments in a fish, its carbon ...

Math - 4.The following table shows the high and low temperatures predicted for ...

calculus - find dy/dx y=ln (secx + tanx) Let u= secx + tan x dy/dx= 1/u * du/dx ...

Pre Calculus - Establish the following identity tan(x+pi/4)=1+tanx/1-tanx