Top answers

Complete the balanced equation for the overall reaction in a hydrogen fuel cell. _ H2 + ___ > _ H2O

Hydrogen fuel cells are really important as they can be used to power electrical cars, so it's something that a lot of scientists are looking into at the moment. We need to balance this equation, so we need ...
KB
Answered by Kyra B. • Chemistry tutor
9468 Views

A and B are points on a circle, centre O. BC is a tangent to the circle. AOC is a straight line. Angle ABO = x°. Find the size of angle ACB, in terms of x. Give your answer in its simplest form. Give reasons for each stage of your working.

(This question is from the Edexcel Higher GCSE paper 2018) As BC is a tangent to the circle, we know that angle OBC must be a right angle (90 degrees)We also know that lines OA and OB are both the same lengt...
RT
Answered by Rachel T. • Maths tutor
12662 Views

By completing the square, find the coordinates of the turning point of the curve with equation y = x^2 + 10x + 2

The equation is in the form ax^2 + bx + c, where a = 1, b = 10 and c = 2To complete the square, we write (x + b/2a)^2 + c - (b/2a)^2So here we would have (x + 5)^2 + 2 - 25Therefore completed square form is ...
NM
Answered by Niamh M. • Maths tutor
8417 Views

Solve x^2 - 3x - 10 = 0 for x by a) factorising and b) the quadratic equation. Then draw a graph of the function, marking when it touches each of the axes.

a) We factorise to find 2 numbers a and b in (x + a)(x + b) such that a + b = -3 and whose product is -10 (ab = -10). (x + 2)(x - 5) = 0 -> x = 5 or -2b) This is a direct application of the quadratic form...
JS
Answered by Joseph S. • Maths tutor
4246 Views

What is the difference between verbs "ser" and "estar"?

Because both verbs can be translated to "to be<" in English, distinguishing them can be particularly difficult for students. The verb "ser" is used to describe permanent/unchangeable s...
AA
Answered by Ariadna A. • Spanish tutor
2370 Views