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I decrease a number by 26%, the answer is 9 x10^-7, what was the original number?

The number has been decreased by 26%, this means that the original number is 100-26=74% of the original value. Therefore 9 x 10 -7 = 0.74 x N, where N is the original number. Hence N=(9 x 10 -7 )/0.74 = 1.21...
LC
Answered by Luke C. • Maths tutor
4582 Views

How do I integrate the volume of revolution between 0 and pi of y=sin(x)?

To integrate the volume of revolution first imagine a thin disk around the x-axis which we want to know the volume of: Volume=area x height. The area of a circle is given by pi r^2 and in our case let us use...
LC
Answered by Luke C. • Maths tutor
4394 Views

Solve: x^2-7x+6=0

Factorise the equation and then equate each set of brackets to 0 to obtain both possible solutions. By factorising: (x-6)(x-1)=0 Therefore: x=6 or x=1
PG
Answered by Phoebe G. • Maths tutor
7170 Views

Line AB has equation 4x+5y+2=0. If the point P=(p, p+5) lies on AB, find P . The point A has coordinates (1, 2). The point C(5, k) is such that AC is perpendicular to AB. Find the value of k.

i) Well, if point P lies in AB, then the value of its x and y coordinates have to fulfill the condition imposed by equation AB. Therefore, substituting the x value p for x and the y value p+5 for y: 4(p)+5(p...
JL
Answered by Javier L. • Maths tutor
5582 Views

Explain why the activity of amylase rapidly decreases above pH 7.

pH 7 is the optimum pH for amylase. This means it performs best and has maximum activity at this pH. Above pH 7, the activity of amylase rapidly decreases beacuse the concentration of H+ ions (or protons) is...
ER
Answered by Emilia R. • Biology tutor
59497 Views