Question

can anyone explain me. How a=rcos thetea and b=rsin theta.

Answer 1

Answer:

Step-by-step explanation:

given a triangle

        now   b is opposite side

                   a is adjacent side

                    r is hypotenuse with respect to theta

                sinФ = opposite side/hypotenuse  =  b/r

                                 sinФ  =  b/r

                                   rsinФ  =  b

            cosФ  =  adjacent/hypotenuse  =  a/r

                                   cosФ =  a/r

                                    rcos Ф = a

     hope this helps u