Cosine theorem?
this formula is used in triangles to define either a cosine or the side of the triangle opposite of the cosine's angle
c2=a2+b2-2abcosc
cosc= the cosine of the angle opposite of the c side of the triangle ABC
hence cosc=(a2+b2-c2)/2ab hereby the same is true for cosa where cosa is the cosine of the angle opposite of the a side and for cosb where cosb is the cosine of the angle opposite of the side b in the triangle
PA
Related Maths GCSE answers
All answers ▸If the area of a rectangle with sides 3cm and (4+x)cm is equal to that of a triangle with base of 2xcm and a height of 4cm, find x
Work out the values of x and y using the equations 2x + 3y = 18 and x + y = 6
Solve the simultaneous equation: (16^x)/(8^y)=1/4 and (4^x)(2^y)=16
The area of square ABCD is 10 cm^2 . Show that x^2 + 6x = 1 (requires diagram which I will draw on the whiteboard).