y=5x2-2x+3 Differentiate to find the equation of the gradient of the curve
dy/dx=10x-2 Substitute x=0 to find the gradient at the point x=0
dy/dx=-2
y=50^2-20+3 Substitute x=0 into the original equation to find y at that point
y=3
y=mx+c Using y=mx+c and substituting x=0, y=3 and m=-2 to find c
3=-2*0+c
c=3 Substitute m=-2 and c=3 to find the equation of the tangent
y=-2x+3