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Start by differentiating the function to find points where the gradient is 0. so dy/dx = 15x^2 + 18x + 3 We can use the equation for finding the roots of a quadratic here, set a=15, b=18 and c=3 and proc...

The question is asking you to find the value of x, x represents a number. Therefore, 7x means 7 times a number- this the number we are trying to find out. The first step is to get all the numbers containi...

y=3x+2 x^2+y^2=20 x^2+(3x+2)^2=20 x^2+(3x+2)(3x+2)=20 x^2+(9x^2+6x+6x+4)=20 x^2+(9x^2+12x+4)=20 10x^2+12x+4=20 10x^2+12x-16=0 5x^2+6x-8=0 (5x-4)(x+2)=0 5x-4=0, x+2=0 x=4/5=0.8, x=-2 y=3x+2, y=3x+2 y=3(0.8...

By using the quadratic quation, it can be deduced that x = 1.22 or x = -3.55

We have to use the chain rule here. If we set u to the inside of the bracket, u = x^2 + 3 and differentiating we get du/dx = 2x. Now the original expression becomes y = u^2. Differentiating this with resp...