Search our library of homework questions

Top answers

All subjects

All levels

Solve 4cos(2x )+ 2sin(2x) = 1 given -90° < x < 90°. Write 4cos(2x )+ 2sin(2x) in the form Rcos(2x - a), where R and a are constants.

Step 1: Recognise 4cos(2x )+ 2sin(2x) must be put into the form given in the question form i.e. Rcos(2x - a) as it contains only one trigonometric function

Step 2: Calculate values of R and a

Answered by Prannay K. • Maths tutor

17113 Views

If cos(x)= 1/3 and x is acute, then find tan(x).

Consider a right angled triangle. Call one of the angles (not the right angle) in this triangle x. We can do this as we are told x is acute. The side opposite to x label O, the side adjacent to x label A,...

Answered by Hugh K. • Maths tutor

18400 Views

If n is an integer prove (n+3)^(2)-n^(2) is never even.

Let us begin by simplifying the expression:(n+3)² - n² = (n+3)(n+3) - n²= n² + 6n + 9 - n² (expanded brackets)= 6n + 9 (collected like terms)= 3(2n+3...

Answered by Hugh K. • Maths tutor

6930 Views

For what values of k does the graph y=x^(2)+2kx+5 not intersect the x-axis

Where the graph intersects the x-axis, x²+2kx+5 must be equal to zero. Thus we can answer the equivalent question: For what k does x²+2kx+5 = 0 not have a solution?This is now a simp...

Answered by Hugh K. • Maths tutor

29554 Views