Tuesday

October 21, 2014

October 21, 2014

Posted by **Pam** on Friday, April 25, 2008 at 7:59am.

find an equation for tangent line y=-1-8^2@ (-4,-129)

find the derivative of the function:----we both kept getting the same answer, but Mathlab kept saying that it was wrong: -4lnl3xl/2+3x

we did the quotient rule, and the chain rule...the derivative and our sign would be wrong...

- calculus -
**Reiny**, Friday, April 25, 2008 at 8:21amI cannot make sense out of your equation, check your typing.

- calculus -
**Pam**, Friday, April 25, 2008 at 11:39am-4 ln l3xl

2+3x

-4ln absolute value of 3x over 2+3x

y= -1-8x^2

(-4,-129)

the first set is in fraction form.

the 3x is absolute.

the 8x^2 is 8x squared.

- calculus -
- calculus -
**Reiny**, Friday, April 25, 2008 at 12:33pmfor the derivative using the quotient rule I got (-8 - 12x + 12x(ln(3x))) / (x(2+3x)^2)

for the tangent question

dy/dx = -16x

at the point the slope is -16(-4) = 64

so using y = mx + b for the tangent equation

-129 = 64(-4) + b

b = 127

so the tangent equation is y = 64x + 127

- calculus -
**Pam**, Friday, April 25, 2008 at 12:45pmThanks. One small error? I can see what we did wrong..we did not do the

-129= part.....guess we were tired, or tried to do it in our heads.

- calculus -

**Answer this Question**

**Related Questions**

Calculus - Tangent Line - Hi, im having problems with the following problem. The...

calculus - what is the derivative? - Let f(x) = 2x^2 + 1 a. Find the derivative ...

Calculus - Damon - Find the line which passes through the point (0, 1/4) and is ...

Calculus - If F(x)=x^3−7x+5, use the limit definition of the derivative to...

Calculus - I am unsure of how to take the derivative of this equation. It may be...

Derivative Calculus - I just need my answers checked. 1) Find the derivative. f(...

secant line, tangent line - f(x) = sqrt(x-1), 1<=x<=3 Let A = (a,f(a)), ...

Math please help - Find an equation of the line that is tangent to the graph of ...

HS Calculus - Definition of the derivative to calculate f'(x) if f(x) = square ...

Calculus - Find the equation of the tangent to the graph of f(x)=2x^4 (to the ...