Prove without a calculator:
tan(50)*tan(25)*tan(75) - tan(75)+tan(50)+tan(25)=0
2007-10-19 11:14:47 · 4 answers · asked by Amir B 1 in Science & Mathematics ➔ Mathematics
use this formula
tan(a-b) = (tan(a)-tan(b))/(1+tan(a)tan(b))
a=75, b=50 a-b=25
tan25 = (tan75-tan50)/(1 +tan75tan50)
tan25*(1+tan75tan50) = tan75-tan50
tan25 + tan75tan50tan25 = tan 75 - tan 50
tan75tan50tan25 - tan75 +tan50 + tan25 = 0
2007-10-19 11:22:55 · answer #1 · answered by norman 7 · 2⤊ 0⤋
I prove that you are wrong;
tan(25) = 0.466307658155
tan(50) = 1.19175359259421
tan(75) = 3.73205080756888
their sum = 5.39011205831809
and
their product = 2.07398955681968
totally different !!!
2007-10-19 18:39:25 · answer #2 · answered by vlee1225 6 · 0⤊ 0⤋
Er...
tan(50)*tan(25)*tan(75) - tan(75)+tan(50)+tan(25)=0
implies
tan(50)*tan(25)*tan(75) = tan(75)+tan(50)+tan(25)
Since it equals itself, substracting by itself would give 0?
2007-10-19 18:25:24 · answer #3 · answered by Anonymous · 0⤊ 1⤋
it doesnt equal zero i dont think
2007-10-19 18:23:16 · answer #4 · answered by Atius 2 · 0⤊ 2⤋