`tan(-1575^@)`

Find tha value of cos(-1575^@)

Evaluate : 2 cos ^(2) 157.5^(@) -1

The velocity of sound in air at 14^@ C is 340 ms^(-1) .What will it be when the pressure is doubled and temperature is raised to 157.5^@ C ?

tan 10^(@)*tan20^(@)*tan30^(@)*tan40^(@)*tan50^(@)*tan60^@tan70^(@)*tan80^(@)=

tan10^(@) tan 20^(@) tan 30^(@) tan 40^(@) tan 50^(@) tan 60^(@) tan 70^(@) tan 80^(@)=

If A+B=(pi)/(2)rArr Tan A Tan B=1 , rArr Tan(A-B)=(tan A-tan B)/(1+tan A tan B)=(tan A-tan B)/(2) , rArr tan A=tan B+2tan(A-B) , (tan40^(@)+2tan10^(@))*(tan70^(@)-Tan20^(@))=

The value of tan 7^(@) tan 23^(@) tan39^(@) tan 60^(@) tan 51^(@) tan 67^(@) tan 83^(@) is

tan20^(@)+tan40^(@)+tan60^(@)+.........+tan160^(@)+tan180^(@)=

Prove that: (a) tan 20^(@)tan40^(@)tan60^(@)tan 80^(@)=3 (b) tan9^(@)-tan27^(@)-tan63^(@)+tan81^(@)=4