## MYTUTOR SUBJECT ANSWERS

826 views

### y is proportional to x^2. When y is 75, x is 5. Find a formula for y in terms of x

y is proportional to x2 so this means y = A*x2 for some constant A.

When y = 75, x = 5. Put these values in the formula above to find A:

75 = A*25

75/25 = A

A = 3

So y = 3x2

2 years ago

Answered by Thomas, a GCSE Maths tutor with MyTutor

## Still stuck? Get one-to-one help from a personally interviewed subject specialist

#### 780 SUBJECT SPECIALISTS

£18 /hr

Degree: Philosophy, Politics and Economics (Bachelors) - Oxford, Worcester College University

Subjects offered:Maths, Spanish+ 5 more

Maths
Spanish
History
Economics
.TSA. Oxford.
-Personal Statements-
-Oxbridge Preparation-

“I am an aspiring teacher, with a clear and analytic approach to tutoring that comes from an extensive and varied educational background.”

£36 /hr

Degree: Computer Science (Doctorate) - Manchester University

Subjects offered:Maths, Italian+ 3 more

Maths
Italian
ICT
Computing
-Personal Statements-

“PhD Student in Computer Science with a passion for interdisciplinary research and teaching”

£22 /hr

Degree: Medicine (Bachelors) - Birmingham University

Subjects offered:Maths, Latin+ 3 more

Maths
Latin
Biology
-Personal Statements-
-Medical School Preparation-

“About me: Hi, my name is Upasana Topiwala and I am currently in my third year of medical school at the university of Birmingham. I've taken up tutoring in order to inspire my students to appreciate the importance of science in our liv...”

#### About the author

Currently unavailable: no new students

Degree: Mathematics (Bachelors) - Bristol University

Subjects offered:Maths

Maths

“About me:I am a 3rd year Mathematics student at University of Bristol, and have received a 1st in both my first and second year exams. This summer, I received the Mathematics Undergraduate Award for the highest overall mark in second...”

MyTutor guarantee

### You may also like...

#### Posts by Thomas

Differentiate 4x^2 + 2ln3x + e^x

y is proportional to x^2. When y is 75, x is 5. Find a formula for y in terms of x

#### Other GCSE Maths questions

1iii) Solve 7/2x^2+13/4x+1=2

How do you factorise and know if it is a difference of two squares ?

What are the trigonometric functions?

There are 20 coloured balls in a bag. The probability of choosing a red ball at random is 1/4. One more red ball is added. Work out the probability of choosing a red ball.

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this.