Top answers

How do I remember the trigonometry identities from C3 in the exam?

I often find it difficult to remember all the different identities, so what is useful is instead to just remember the familiar identity sin^2(x) + cos^2(x) = 1 that we have come across many times, and divide...
JS
Answered by Joshua S. • Maths tutor
4942 Views

Simplify: 2x +6y +2y - x

collect x terms together i.e.) 2x - X = 1x and then collect y terms together i.e) 6y + 2y = 8y add your two answers together to get: x + 8y Answer x +8y
SM
Answered by Sophie M. • Maths tutor
6879 Views

If a and b are the roots of the quadric polynomial 2x^2+6x+7 what are a+b and ab?

The phrase "a and b are roots of 2x^2+6x+7" is just a way of saying that x=a and x=b solve the equation 2x^2+6x+7=0. Check out that by diving by 2 on both sides of this equation we get that that x=...
GC
Answered by Guillermo C. • Maths tutor
3821 Views

A bag contains beads, 60% of which are green. A student claims that the probability of getting two green beads if the beads aren't replaced is 1/3 as 6/10 * 5/9 is 1/3. Is the student right?

They have multiplied the fractions correctly but they are still incorrect. The student has assumed that a bag with 60% green beads contains 10 beads. If the bag had 100 beads and 60 were green, 60% of the be...
AK
Answered by Adithya K. • Maths tutor
3911 Views

Differentiate with respect to x: y=xln(x)

Recall the product rule for differentiation. If y=uv, where u and v are functions defined by functions of x, then we can take the derivative of y as: y'=u'v+v'u ( ) (where ' denotes the derivative) Applying ...
GP
Answered by George P. • Maths tutor
7249 Views