HELP further maths ;((

[toxic wasp]

still need help?

also yeah it's differentiation

you need to differentiate the equation of the curve to get the gradient of a tangent to the curve at a point

when you differentiate the equation of the curve you get: ||2x + a||

so dy/dx = ||2x + a|| (this is the gradient of the tangent to the curve at a point)

now we just need to substitute the x values we are given into that gradient formula to get the gradient of the tangent to the curve at those points where x = 2 and x = -1

for x = 2:
||2(2) + a|| is the gradient
for x = -1:
||2(-1) + a|| is the gradient

we are told that the gradient of the tangent to the curve at x=2 is twice the one at x=-1 so we can form an equation since we have the gradients for both of those points in terms of a

||4 + a = 2(-2 + a)
4 + a = -4 + 2a||
and so a ||= 8||

marked as spoilers in case you wanted to have a go now that you know the method

lmk if you have any questions