Its from the c3 solomon paper A and the question 4 part b. Whenever i put in x=pi/4 i keep getting a different answer for y to what it says on the mark scheme. Can someone explain how to do it?
Its from the c3 solomon paper A and the question 4 part b. Whenever i put in x=pi/4 i keep getting a different answer for y to what it says on the mark scheme. Can someone explain how to do it?
Thanks
Just to make sure, have you differentiated y before you put x=pi/4 into dy/dx ?
Just to make sure, have you differentiated y before you put x=pi/4 into dy/dx ?
yep, i got dy/dx= 2xsec^2x+2tanx
I don't see where im going wrong afterwards...i might have made a silly mistake somewhere, but i tried putting x in both rad and deg mode and still couldnt get the right answer.
I don't see where im going wrong afterwards...i might have made a silly mistake somewhere, but i tried putting x in both rad and deg mode and still couldnt get the right answer.
You need to work out the equation of the tangent at the point, so put x=pi/4 into the original function (y), to get the corresponding y value for when x=pi/4, then work out dy/dx at pi/4 (make sure you are in radians)
Then use y-y1=m(x-x1)
Form the equation and it meets the y axis when x=0. So then work out y.
You need to work out the equation of the tangent at the point, so put x=pi/4 into the original function (y), to get the corresponding y value for when x=pi/4, then work out dy/dx at pi/4 (make sure you are in radians)
Then use y-y1=m(x-x1)
Form the equation and it meets the y axis when x=0. So then work out y.
Oh okay, so is the grad=5.141592... correct? That's what i kept getting.