Question

If log 3.16=2.49776 then antilog2497. 76

Answer 1

Answer:

The given equation is:

\frac{cos20+sin20}{cos20-sin20}=tan65

Taking the left hand side of the above equation, we get

\frac{cos20+sin20}{cos20-sin20}

\frac{cos20(1+\frac{sin20}{cos20})}{cos20(1-\frac{sin20}{cos20})}

\frac{1+tan20}{1-tan20}

Now, we know that tan45=1, therefore the above equation becomes,

\frac{tan45+tan20}{tan45-tan20}

Using, tan(A+B)=\frac{tanA+tanB}{1-tanAtanB}, the above equation becomes,

tan(45+20)

tan65=RHS

Hence proved.