" 18.यदि "cos A=(4)/(5)," तो सिद्ध कीजिए कि "(tan A)/(1+tan^(2)A)=(sin A)/(sec A)

if cos A=(4)/(5) then prove that (tan A)/(1+tan^(2)A)=(sin A)/(sec A)

सिद्ध कीजिए कि 2tan^(-1)sqrt((b)/(a))=cos^(-1)((a-b)/(a+b))

Prove that (1+sec A-tan A)/(1+sec A+tan A)=1-sin A/(cos A)

If sec alpha=(5)/(4), verify that (tan alpha)/(1+tan^(2)alpha)=(sin alpha)/(sec alpha)

(sin A)/(sec A+tan A-1)+(cos A)/(cos ecA+cot A-1)=1

(1+tan A)/(sin A)+(1+cot A)/(cos A)=2(sec A+cosec A)

Prove: (sec A-tan A)/(sec A+tan A)=(cos^(2)A)/((1+sin A)^(2))

(tan A + sec A-1) / (tan A-sec A + 1) = (1 + sin A) / (cos A)

Show that (tan A .sin A) + cos A = sec A .

Prove that (i) (sec 8A -1)/(sec 4A -1) =(tan 8A)/(tan 2A) (ii) (cos A+ sin A)/(cos A - sin A)-(cos A-sin A)/(cos A+sin A)=2 tan 2A