# Calculus

posted by .

If the equation of the tangent line to the curve y=9cosx

at the point on the curve with x-coordinate 3pi/4 is written in the form y=mx+b then m=? and b=?

• Calculus -

m is the slope of the tangent,
m= d/dx (9cosx)=-9sinx
you are given x, so you can compute m.

then, knowing x,y, put that into y=mx+b to solve for b.

• Calculus -

x would be 3pi/4 correct?

What would 3pi/4 equal approximately? I tried to do -9 * sin * 3pi/4 but I'm not getting the correct answer.

• Calculus -

3pi / 4 is a memory value (use the 45 - 45 - 90 right triangle). If you're not getting the correct answer inputting it into a calculator, you may be in degree mode.

## Similar Questions

1. ### Calculus

the curve: (x)(y^2)-(x^3)(y)=6 (dy/dx)=(3(x^2)y-(y^2))/(2xy-(x^3)) a) find all points on the curve whose x-coordinate is 1 and write an equation for the tangent line of each of these points b)find the x-coordinate of each point on …
2. ### math calculus

Use implicit differentiation to find the equation of the tangent line to the curve xy^3+2xy=9 at the point (31). The equation of this tangent line can be written in the form y=mx+b where m is
3. ### calculus

Consider the curve given by the equation y^3+3x^2y+13=0 a.find dy/dx b. Write an equation for the line tangent to the curve at the point (2,-1) c. Find the minimum y-coordinate of any point on the curve. the work for these would be …
4. ### calculus

-find the equation of the tangent line to the curve y=5xcosx at the point (pi,-5pi) -the equation of this tangent line can be written in the form y=mx+b where m= and b= -what is the answer to m and b?
5. ### calculus

Consider the curve defined by 2y^3+6X^2(y)- 12x^2 +6y=1 . a. Show that dy/dx= (4x-2xy)/(x^2+y^2+1) b. Write an equation of each horizontal tangent line to the curve. c. The line through the origin with slope -1 is tangent to the curve …
6. ### COLLEGE CALCULUS.

Use implicit differentiation to find the equation of the tangent line to the curve xy^3+xy=5 at the point (4,1) . The equation of this tangent line can be written in the form y = mx+b where m is:?
7. ### Calculus. I need help!

HARDER PARTS WAS 3(x^2+y^2)^2=26(y^2+y^2) Find the equation of the tangent line to the curve (a lemniscate) 3(x^2+y^2)^2=26(y^2+y^2) at the point (-4,2). The equation of this tangent line can be written in the form y=mx+b where m is:?
8. ### Calculus 251

The slope of the tangent line to the curve y= 3x^3 at the point (-1,-3) is:?
9. ### Calculus

the slope of the tangent line to the curve y=(3/x) at the point (6,0.5000) is?