Core 3 Differentiation

Question: Show that the value of the gradient of the curve with equation y = sin2x / x at the point where x = pi/2 is -4/pi.

I have differentiated y = sin2x / x but when I substitute pi/2 in it comes out at a decimal. How do I achieve an answer of -4/pi?

Thanks.

There ya go.

Just a heads up, you're not supposed to tell them the answer directly. Instead, you're supposed to help them get the answer. Please see the rules on the sticky: http://www.thestudentroom.co.uk/showthread.php?t=403989

Oh, I see. This is why I have no plans to go into teaching.

Question: Show that the value of the gradient of the curve with equation y = sin2x / x at the point where x = pi/2 is -4/pi.

I have differentiated y = sin2x / x but when I substitute pi/2 in it comes out at a decimal. How do I achieve an answer of -4/pi?

Thanks.