Top answers

Maths
All levels

Show, by counter-example, that the statement "If cos(a) = cos(b) then sin(a) = sin(b)" is false.

Let a=60 and b=300.

Then cos(a)=cos(60)=0.5 and cos(b)=cos(300)=0.5, therefore cos(a)=cos(b).

Then sin(a)=sin(60)=sqrt(3)/2 and sin(b)=sin(300)=-sqrt(3)/2, therefore sin(a)=sin(b) is incorre...

Answered by Osian G. Maths tutor
3779 Views

Differentiate y(x)=x^2 + 2x + 1, find the turning point and classify it as minimum or maximum.

dy/dx=2x + 2

Turning point is where dy/dx=0, so when x = -1

When x=-1, y=0.

d^2y/dx^2=2 > 0 therefore minimum.

Answered by John F. Maths tutor
3680 Views

Differentiate (3x)e^(3x)

3e^3x + (9x)e^3x This is a good question because it involves the use of both the chain and product rules of differentiation, as well as the differential of e (all of which occur frequently in Maths A-leve...

Answered by Joe H. Maths tutor
3400 Views

The second term of an arithmetic sequence is 7. The sum of the first four terms of the arithmetic sequence is 12. Find the first term, a, and the common difference, d, of the sequence.

Let a be the first term

Let d be the common difference

a + d = 7

S4 = 4/2 (2a +3d) = 12

Simultaneous equation:

a+d =7 // x 6
4a +6d = 12

Differen...

Answered by Alexander T. Maths tutor
20594 Views

Integrate 5cos(3x - 1) with respect to x

Firstly, we may simplify the expression by factoring out any constants. In this case 5 can be factored out. 

5 ∫ cos(3x-1) dx 

For the integrand cos(3x -1), we can use a simple u-substitutio...

Answered by Rian M. Maths tutor
5119 Views

We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences