 Hi and welcome to the session. Let's work out the following question. The question says without using tables evaluate cos 70 degree by sin 20 degree plus cos 55 degree into cos 35 degree divided by tan 5 degree into tan 25 degree into tan 45 degree multiplied by tan 65 degree multiplied by tan 85 degree. Let us see the solution to this question. Now we see that this can be written as, first to call we consider the first term here. The numerator can be written as cos 90 degree minus 20 degree divided by sin 20 degree plus cos 90 degree minus 35 degree into cos 35 degree divided by tan 5 degree into tan 25 degree. Now tan 45 degree is 1 into tan 90 degree minus 25 degree into tan 90 degree minus 5 degree. This can be written as sin 20 degree by sin 20 degree because cos 90 degree minus 20 degree is same as sin 20 degree plus sin 35 degree into cos 35 degree is same as 1 upon sin 35 degree divided by tan 5 degree into tan 25 degree into 1 into cos 25 degree into cos 5 degree. This is equal to 1 plus this gets cancelled with this and the denominator here also becomes 1. This is 1 plus 1 that is equal to 2. This happens because we see that tan theta into cos theta is equal to 1. So our answer to this question is 2. I hope that you understood the solution and enjoyed the session. Have a good day.