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(x+2)(x-3)

Multiply the first term in the first bracket, so that would be x, with the second bracket. step one: x(x-3) is identical to: x^2 - 3x We can now multiply the second number in the first bracket, which would b...
LW
Answered by Lai Wah T. • Maths tutor
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y = 4x^3 - 5/x^2 Find dy/dx

y = 4x^3 - 5/x^2 Easier to differentiate the 2nd term if it isn't written as a fraction so first rewrite y: y = 4x^3 - 5x^(-2) Then differentiate each term by multiplying each term by the current power of x ...
NC
Answered by Nisha C. • Maths tutor
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Using the Trapezium rule with four ordinates (three strips), estimate to 4 significant figures the integral from 1 to 4 of (x^3+12)/4sqrt(x). Calculate the exact value of this integral, comparing it with your estimate. How could the estimate be improved?

Taking the value at the ordinates f(1) = 13/4, f(2) = 20/4sqrt(2), f(3) = 39/4sqrt(3), f(4) = 9.5 Then the trapezium rule states the integral is approximately 1/2 * [f(1) + 2f(2) + 2f(3) + f(4)], which (usin...
RM
Answered by Robert M. • Maths tutor
8502 Views

How do I differentiate a trigonometric function for something that is not just a single variable (e.g. d/dx (sin(3x))?

In order to differentiate a trig function with a term in front of the variable you are differentiating, you must use the chain rule. For example d/dx (sin (3x)) becomes 3cos(3x) because you have to multiply ...
KT
Answered by Kieran T. • Maths tutor
5376 Views

What is De Moivre's theorem?

De Moivres theorem states that e^j(theta) = cos (theta) +jsin (theta) and this can be used to convert powered trig functions to the form of regular sines and cosines (i.e. sin^3(x) into a sum of terms includ...
KT
Answered by Kieran T. • Maths tutor
5768 Views