Question

If sec alpha=5/4,evaluate(1-tan alpha/1+tan alpha)?

Answer 1

hey friend its very easy first of all see at what value of α,secα= 5/4 we know that the value of cos 37=4/5 so the value of alpha will be 37 degree
Now, write tan(45-α) and by the property of tanα it will be equal to$\frac{tan45-tan α}{tan45+tanα}$ nad this will be equal to 
$\frac{1-tan \alpha }{1+tan \alpha }$
so the value of that tanα term that you have given in the question will be tan(45-α)
Now,put the value of α that we have got above 
so the answer will be
tan(45-37)=tan8