I need to know the value of x in this triangle

What basic trigonometric identity would you use to verify that sin x cos x tan x =1-cos^(2)x?

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

What kind of bond pays interest which is exempt from tax?