Top answers

Find the gradient of y=x^2-6x-16 at the point where the curve crosses the x-axis

So we have y = 0 and therefore x 2 - 6x - 16 =0 This is then factorised to (x+2)(x-8) = 0 and therefore we have x = -2, x = -8 To find the gradient we need to find dy/dx So dy/dx = 2x - 6 Therefore if x = -2...
HK
Answered by Holly K. • Maths tutor
4920 Views

How do I know which trigonometric identity to use in any given situation?

For the most part, this comes down to practice. The insight in seeing which identity gives you the most efficient path to the solution comes with experience, however a little trick I like to use (silly as it...
AT
Answered by Ankush T. • Maths tutor
4154 Views

Find values of y such that: log2(11y–3)–log2(3) –2log2(y) = 1

NB.: Treat all log as log2 for purpose of formatting log(x) - log(z) = log(x/z) alog(b) = log(b^a) log((11y - 3)/3) - log(y^2) = 1 log((11y - 3)/3y^2) = 1 11y - 3 / 3y^2 = 2^1 11y - 3 = 6y^2 6y^2 - 11y + 3 =...
SA
Answered by Shrinivas A. • Maths tutor
6238 Views

How do you add and multiply surds?

When you add and subtract surds, the numbers inside the square root must be the same. You add/ subtract the number outside the square root. e.g. 2√5 + 7√5 = 9√5, however 2√5 + 7√3 cannot be added. when you m...
GC
Answered by Grace C. • Maths tutor
75152 Views

Two identical cuboids have dimensions of 4cm by 6cm by 12cm. What is their combined volume?

4cm*6cm = 24cm 2 (End face) 24cm 2 *12cm = 288cm 3 (Volume of one cuboid) 288cm 3 *2 = 576cm 3 (Volume of two cuboids)
AG
Answered by Alex G. • Maths tutor
4021 Views