Top answers

A is a function of P . It is known that A is the sum of two parts, one part varies as P and the other part varies as the square of P . When P = 24 , A = 36 and when P = 18 , A = 9. Express A in terms of P .

Let A = aP + bP2 , where a and b are constants. Sub. P = 24 , A = 36 , 24a + 576b = 36 2a + 48b = 3 ………… (1) Sub. P = 18 , A = 9 , 18a + 324b = 9 2a + 36b = 1 ………… (2) Solving (1) and (2) a=-5/2 b=1/6 ∴A=-5/...
CY
Answered by Chun Yin L. • Maths tutor
13917 Views

What is the derivative of ln(x)?

First let y=ln(x). Recall that the exponential function, e x , is defined as the inverse of the logarithmic function, ln(x). To make x the subject of the formula, use the inverse function exp. This gives tha...
BG
Answered by Benjamin G. • Maths tutor
11660 Views

Why is it that sin^2(x) + cos^2(x) = 1?

Let's start with the definition of sin( x ) and cos( x ). We're going to use t rather than x here to avoid confusion, but the idea is exactly the same. Take a unit circle - that is, a circle with centre (0,0...
JT
Answered by John T. • Maths tutor
7447 Views

How do I sketch a graph of a polynomial function?

To sketch a polynomial function (a polynomial is a function involving powers of x, for example y = x 3 + 2x 2 - 13x + 10): 1. Start by differentiating the function to find its turning points (where the first...
RA
Answered by Rose A. • Maths tutor
9521 Views

Find dy/dx for y=5x^3-2x^2+7x-15

Step 1: To differentiate an equation there is a simple rule to follow. For y=ax n dy/dx=anx n-1 . so for an example y=x 3 , dy/dx=3x 2. Therefore we just apply this rule into our equation. Step 2: Break the ...
MT
Answered by Matthew T. • Maths tutor
13271 Views