(2cosA+1) (2cosA-1)=2cos2A+1 prove that

Step-by-step explanation:

We need to prove that ,

We can start by taking RHS and will try to obtain the LHS . The RHS is ,

We know that , cos2A = 2cos²A - 1 ,

Simplify the bracket ,

Add the constants ,

Write each term in form of square of a number ,

Using (a+b)(a-b) = a² - b² , we have ,

This equals to LHS , therefore ,

Hence Proved !

they can both be solutions depends on the equation

step-by-step explanation:

what is the equation? ?

answer: 10 turtles

step-by-step explanation: as turtles have four legs so 4.10=40 therefore birds are 4 which sue counted