Divide 3 by 15 to get 1/5. If you divide 1 by 5, you will get a decimal answer of 0.2. To convert a decimal to a percent, you must multiply the decimal by 100, which basically means to move the decimal place to the right twice. You will then get the product and final answer of 20%.
Sin 2 x + 2 sin x = 0 2 sin x cos x + 2 sin x = 0 / : 2 sin x cos x + sin x = 0 sin x ( cos x + 1 ) = 0 sin x = 0, cos x + 1 = 0, cos x = - 1; Answer: x = 0, or x = π