If a is acute and cosa=5/13 find cos2a

Empty box + box + empty box fill in the box is equal to 30 how

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0

Answer asap ill give ! ’ a sample of radioactive material decays over time. the number of grams, y , of the material remaining x days after the sample is discovered is given by the equation y = 10(0.5)^x. what does the number 10 represents in the equation? a. the half-life of the radioactive material, in days b. the amount of the sample, in grams, that decays each day c. the time, in days, it will take for the samples to decay completely d. the size of the sample, in grams, at the time the material was discovered