Calculus of Trigonometry Question (1 Viewer)

[Focus is Key]

The question is: Find the equation of the tangent to curve y=sin3x where x=Pi/4 and y=1/Root 2.

I really am having trouble manipulating it :/ Thanks guys

 

[Parvee]

The question is: Find the equation of the tangent to curve y=sin3x where x=Pi/4 and y=1/Root 2.

I really am having trouble manipulating it :/ Thanks guys

Find the gradient of the curve and then use y-y1=m(x-x1)
where y1=1/root2 and x1=pi/4

 

[yasminee96]

dy/dx = 3cos3x
dy/dx (pi/4) = -3/sqrt2

y-y1=m(x-x1)
y-1/sqrt2 =-3/sqrt2 (x-pi/4)
y.sqrt2 -1 =-3x +3pi/4

 

[Focus is Key]

Thanks guys, forgot the times by 3 once I had done Pi/4. Thanks :3