Simplify, using trigonometric tables

sin 50° 26’ + cos 18° + tan 70° 12’

First, we consider sin 50° 26’,

We write sin 50° 26’ = sin 50° 24’ + 2’.

The relevant part of the sine table is given below.

From the table, we have

Sin 50° 24’ = 0.7705

Mean difference for 2’ = 0.0004

We know that mean difference is to be added in the case of sine.

∴ sin50° 26’ = 0.7705 + 0.0004 = 0.7709

Now consider cos 18°,

The relevant part of the cosine table is given below.

From the table, we have

cos 18° = 0.9511

Then consider tan 70° 12’,

The relevant part of the tangent table is given below.

From the table, we have

tan 70° 12’ = 2.7776

∴ sin 50° 26’ + cos 18° + tan 70° 12’ = 0.7709 + 0.9511 + 2.7776 = 4.4996