Question

Please can anyone say me what the symbol after cos written in the picture called and where it is? used​

Answer 1

Answer:

∅set with no elements..... the diameter sign.

Step-by-step explanation:

Answer 2

Answer:

Cosine

Step-by-step explanation:

The cosine rule is used when we are given either a) three sides or b) two sides and the included angle.The ratio of the adjacent side of a right triangle to the hypotenuse is called the cosine and given the symbol cos.