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You area told that y is proportional to x2 and that when y = 75, x = 5. a) Find a formula for y in terms of x. b) Find the value of y when x = 3. c) Find the value of x when y = 1200.

a) when y=75 x=5 and y is proportional to x^2, so the answer is y=___x^2
if x=5, then x^2 = 25, and 75/25=3, so the answer is y=3x^2

b) if x=3, x^2=9, if you multiply this by 3, you get the a...

Answered by Millie B. • Maths tutor

3429 Views

Express 3cos(theta) + 5sin(theta) in the form Rcos(theta - alpha) where R and alpha are constants, R>0 and 0<alpha<90. Give the exact value of R and the value of alpha to 2dp.

Write out identity:

Rcos(theta - alpha) = Rcos(theta)cos(alpha) + Rsin(theta)sin(alpha) from formula booklet

Write out in form of question so it's easier to compare:

3cos(theta) + 5si...

Answered by Olivia S. • Maths tutor

14602 Views

What is the difference between a Bronsted Lowry acid and a Lewis Acid?

In chemistry there are two distinct theories to explain acid-base reactions; the Bronsted-Lowry and Lewis acid-base theories. The Bronsted-Lowry theory talks about removal or transfer of ...

Answered by Michael E. • Chemistry tutor

42854 Views

how to write down the differential equation from a word problem, involving rate of change.

Read the word problem more than once to make sure you fully understand what is being asked and write down the variables involved. Then try to write down all the derivatives in terms of each other, using t...

Answered by Christoforos G. • Maths tutor

3126 Views