Search our library of Maths questions

Top answers

Maths

All levels

y is inversely proportional to d2 when d = 10, y = 4 d is directly proportional to x2 when x = 2, d = 24 Find a formula for y in terms of x. Give your answer in its simplest form.

y=k/d²
substituting:4=k/10²
4=k/100
400=k
d=nx²
substituting:24=n x 2²

24=4n
n=6
Eq1:y=400/d²
Eq2:...

12732 Views

Integrate Sin^2(x)

(using double angle formula)Sin^2(x)=1/2-(Cos(2x)/2)
So the Integral is 1/2(x-1/2Sin(2x))which simplifies to x/2 - 1/2Sin(x)Cos(x)

Answered by Alex R. • Maths tutor

3294 Views

The perimeter of a right-angled triangle is 72 cm. The lengths of its sides are in the ratio 3 : 4 : 5. Work out the area of the triangle.

Consider a right angled triangle, it has perimeter of 72cm. Let's label the three sides a, b and c.Therefore, a + b + c = 72cm.Also, we know that a:b:c = 3:4:5Therefore we can say that a = 3x, b = 4x, c =...

Answered by Dilan A. • Maths tutor

2449 Views

Express 6cos(2x)+sin(x) in terms of sin(x). Hence solve the equation 6cos(2x) + sin(x) = 0, for 0° <= x <= 360°.

Firstly, we need to express 6cos(2x) + sin(x) in terms of sin(x) 6cos(2x) + sin(x) = 6cos(x+x) + sin(x) = 6cos²(x) - 6sin²(x) + sin(x) (applying cos(x+y) = cos(x)cos(y) - sin(x)sin(y...

Answered by Dilan A. • Maths tutor

3789 Views

A curve has equation x^2 +2xy–3y^2 +16=0. Find the coordinates of the points on the curve where dy/dx = 0.

x² +2xy–3y²+16=0Differentiate the terms:x² gives 2x2xy is differentiated by the product rule: vu' +v'u Make v = 2x and u = y, which gives 2x(dy/dx) + 2y3y² give...

Answered by Dilan A. • Maths tutor

10313 Views