Question

tan20.tan10.tan45.tan.70.tan80 =1​

Answer 1

Step-by-step explanation:

As we know,

tan×cot=1

Now, tan20°×tan80°=1

tan10°×tan70°=1

and, tan45=1

Thus, the answer is 1×1×1=1

Hence, proved

Answer 2

Step-by-step explanation:

first of all ,put the corresponding no. s ,tan 20 with tan 70 and tan 10 with tan 80

then , as u know the value of tan 45 is 1

and after changing tan 70 into cot (90 -70) & tan 80 into (90-80)

u would get the sol. as 1