Top answers

Use the addition formulas: sin(x+y)=sin(x)*cos(y)+sin(y)*cos(x), cos(x+y)=cos(x)*cos(y)-sin(x)*sin(y) to derive sin(2x), cos(2x), sin(x)+sin(y).

sin(2x)=sin(x+x) =sin(x)cos(x)+cos(x)sin(x) =2*sin(x)*cos(x); cos(2x)=cos(x+x) =cos(x)cos(x)-sin(x)sin(x) =[cos(x)] 2 -[sin(x)] 2 Now let x+y=a and x-y=b, then x=(a+b)/2 and y=(a-b)/2. Then sin(a)=sin[(a+b)/...
IS
Answered by Ioana S. • Maths tutor
4823 Views

Why do you need simultaneous equations?

This is an example of a simultaneous equation - 2X + Y = 5X + 3Y = 10 You can think of X and Y as apples and oranges from a market. You know that if you buy 2 apples and 1 orange it cost £5, but this doesn’t...
AG
Answered by Amelia G. • Maths tutor
3540 Views

Describir unas de las vacaciones del ano pasado. Escribir entre 80 y 90 palabras.

El año pasado, fui a Grecia con mis padres y mi mejor amigo que se llama Jack. ¡Lo pasé bomba! He estado yendo a Grecia desde que tenía ocho años. Todos los días fuimos a la playa y nadamos en el mar. Además...
AK
Answered by Arron K. • Spanish tutor
3716 Views

How do you conjugate the future tense in French?

There are two ways to make the future tense in French:The first is generally used to describe things that will happen in the near future. The French near future uses the verb “aller” (to go) in the present t...
NW
Answered by Naoise W. • French tutor
2645 Views

What is the difference between an offer and an invitation to treat

An offer may be defined as a statement showing a desire to contract on certain terms and to be legally bound by those terms. On the other hand, an invitation to treat is only inviting the party to make an of...
NW
Answered by Naoise W. • Law tutor
59837 Views