Search our library of Maths questions

Top answers

Maths

All levels

Can I take a derivative at x=0 for the function f(x) = |x| ?

Just because a function is continuous at a point, that doesn't mean it has a derivative at that point. If a function is differentiable on an interval, then it is continuous on that interval, but the rever...

Answered by Tutor68168 D. • Maths tutor

6376 Views

Rationalise the denominator of \frac{6}{\sqrt{2}}.

When rationalising, multiply the fraction by the denominator - so what that means is multiply the fraction by the square rooted number over the square rooted number. The numerators then multiply to give 6...

Answered by Akash R. • Maths tutor

5051 Views

Using the "complete the square" method, solve the following x^2 +4x - 21 =0

x²+4x-21= 0, This can be factorised into brackets as shown: (x+2)²- 4 - 21 = 0 SImplified, so all x's are on one side of the equation: (x+2)²= 25, Removing square root,...

Answered by Charlotte S. • Maths tutor

6105 Views

Given a circle with the equation y^2 + x^2 = 10, with a tangent that intersects at point P, where x=1, find the coordinates for the point at which the tangent meets the x axis (Q).

As the tangent meets the circle at P, when x =1, we can assume that the y value will be the same for this value of x. therefore we substitute x=1 into the equation of the cirlce. Rearranging the equation ...

Answered by Joseph P. • Maths tutor

5309 Views