2007-03-29 01:38:53 · 5 answers · asked by Lyubov L 1 in Science & Mathematics ➔ Mathematics
sin(x) = 1/4 = opp/hyp
opp = 1
hyp = 4
adj = sqrt(4^2 - 1^2) = sqrt(16 - 1) = sqrt(15)
cos(x) = adj/hyp = sqrt(15)/4
2007-03-29 01:41:47 · answer #1 · answered by Puggy 7 · 0⤊ 0⤋
Given: sin(x)=1/4 , 0 < x < pi/2
As x is between 0 and pi/2, the angle is in the first quardrant.
This means cos(x) is positive OR x is acute.
sin sqr(x) + cos sqr(x) =1
therefore, cos sqr(x) =1-1/16 =15/16
therefore, cos(x) =sqr.root(15/16) = "sqr.root15/4"
2007-03-29 09:06:22 · answer #2 · answered by v.neo 1 · 0⤊ 0⤋
By pythagoras
cos (x) = SQRT(4^2-1^2)/4
= SQRT(15)/4
2007-03-29 08:41:48 · answer #3 · answered by Orinoco 7 · 0⤊ 0⤋
The restriction means x is acute and so cos x is positive.
cos x =â(1 - (sin x)^2)
cos x = â15/4
2007-03-29 08:44:15 · answer #4 · answered by Hy 7 · 0⤊ 0⤋
Ey?
2007-03-29 08:41:42 · answer #5 · answered by emaf1uk 4 · 0⤊ 0⤋