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Show that the curve with equation y=x^2-6x+9 and the line with equation y=-x do not intersect.

First, you equate the 2 equations to get this single quadratic equation (x^2-5x+9=0). And then evaluate the expression b^2-4ac. If b^2 -4ac is < 0 then they do not intersect. In our case b^2 -4ac is -9...

Answered by Foday K. • Maths tutor

3454 Views

A GCSE is graded out of 140 marks. 1/5 of these marks were given for coursework. The rest were divided between two reading and listening tests, with the marks split in the ratio 3:4 respectively. How many marks were given for the reading test?

140/5 = 28140 - 28 = 1123 + 4 = 7112/7 = 1616 x 3 = 48Answer: 48 (Would go through methods with student: order of thinking, dealing with ratio, long division)

Answered by Will B. • Maths tutor

3401 Views

The line L has equation 7x - 2y + 11 = 0, Find the gradient of l

First rearrange the equation to get 2y = 7x + 11.Then divide through by 2 to get the equation for y: y=7x/2 +11/2Now differentiate with respect to x to find the gradient function: dy/dx=7/2 + 0We hav...

Answered by Gabriel H. • Maths tutor

4031 Views

How do you know if a stationary point on a curve is a maximum or minimum without plotting the graph?

Once you have found the stationary point of the equation by differentiating the equation and equating it to zero. You can then find out if the point you have found is a maximum, minimum or point of inflec...

Answered by Sam G. • Maths tutor

3761 Views

The equation 5x^2 + px + q = 0, where p and q are constants, has roots t and t+4. Show that p^2 = 20q + 400.

We know that if we have a polinomial of the form ax^2 + bx + c = 0, then:sum of the roots = -b/a and product of the roots = c/a Therefore: t + (t + 4) = -p/5 and t(t + 4) = q/5 Therefore: 2t + 4 = -p...

Answered by Alexandra B. • Maths tutor

3994 Views