Given cos x= 1/4 with 0 < x < pi/2 find cos x/2

Since 0 < x < π/2, we know 0 < x/2 < π/4, so that cos(x/2) is still positive.

Recall the double-angle formula,

cos²(x/2) = (1 + cos(x)) / 2

so that

cos(x/2) = √((1 + 1/4) / 2) = √(5/8)

answer: $420.00

step-by-step explanation:   multiply $400.00 by 5%.

400.00*.05=20

400+20 = 420

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.