Question

without using Trigonometric Table prove that tan48 tan23 tan42 tan67 tan 45 equal to 1​

Answer 1

Step-by-step explanation:

tan 48 tan 23 tan 42 tan 67 tan 45=1

L.H.S = tan(45+3) tan(45- 22) tan(45-3) tan(45+22) tan 45 = (tan45+tan3)(tan45-tan22) (tan 45 -tan3)(tan 45+tan22)(1)

_________. _________ ________ __________

1 -tan45tan3 1+tan45tan22 1+tan45tan3. 1-tan45tan22

=(1+tan3) (1-tan22) (1-tan3) (1+tan22)

______ ______ _____ _______

1-tan3 1+tan22. 1+tan3. 1-tan22

All values are cancelled out

=》 1. = R.H.S

Hence proved that L.H.S=R.H.S