Ptolemy a) Prove the sum formula, 120 crd(180º – (a + b)) = crd(180° – a) crd(180° – B) – crd(a) crd(B), using Ptolemy's formula on quadrilaterals inscribed in a circle. b) Use Ptolemy's difference formula to calculate crd(12°) and then apply the half-angle formula to calculate crd(6°) and crd(30). Note: Use decimal numerical system for your calculations. You may use that crd(72°) = 70; 32, 3. Compare your result to Ptolemy's: crd(3°) = 3; 8, 28 and crd(69) = 6; 16; 49.

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

You have just applied, and have been approved for a $58,000 mortgage. the rate quoted to you by the lender is 6.1% for a 30 year fixed mortgage. determine how much of your third month’s payment goes towards the principal. $56.65 $56.93 $57.22 $57.51

Ms.lopez has 4 liters of chemicals that she is going to pour into beakers. each beaker will have 1/4 of a liter of chemicals, how many beakers can ms.lopez fill? draw a model to support your work. (it's ok if you dont)