Top answers

Show that sin2A is equal to 2sinAcosA

This question requires you to use the trigonometric identity sin(A+B)=sinAcosB + sinBcosA. The difficulty in this problem is noticing that you need to substitute 2A for A+A and then you can simply put this i...
SL
Answered by Samuel L. • Maths tutor
39218 Views

N=2a+b, where a is a two-digit square number and b is a two-digit cube number. What is the smallest possible value of N?

Considering the smallest possible value of N will mean finding the smallest possible values of a and b to give the minimum N. As a must be a square number, let's consider the square numbers: 1 squared is 1; ...
KH
Answered by Katherine H. • Maths tutor
8724 Views

Solve the following simultaneous equations: 2a-5b=11, 3a+2b=7

Let 2a-5b=11 be Equation 1 and 3a+2b=7 be Equation 2. To find a and b, we first need to eliminate one of these variables from the equation. Firstly we can eliminate a from both equations to find b. To do thi...
GC
Answered by Gemma C. • Maths tutor
17248 Views

If y = 2(x^2+1)^3, what is dy/dx?

Since the equation for y is a composite function (applying one function to another function) we need to use the chain rule to answer this question. Firstly let u = x^2+1 . This allows us to write y = 2u^3. D...
GC
Answered by Gemma C. • Maths tutor
4635 Views

Write down 9.02x10^-3 and 2.6x10^5?

All you have to do for 9.02x10^-3 is put 0.00902 which is basically putting 0.(because of 10^-3) and move two decimal places and put 902. 2.6x10^5 is a positive power of 10 hence you have to add four zeros n...
HI
Answered by Hamza I. • Maths tutor
6532 Views