Prove the identity cos(x-y)-cos(x+y)=2sinxsiny

Find parametric equations for the line tangent to the curve of intersection of the surfaces at the given point. surfaces: xsquared2plus+2yplus+2zequals=1212 yequals=33 point: left parenthesis 1 comma 3 comma five halves right parenthesis

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Marco is studying a type of mold that grows at a fast rate. he created the function f(x) = 345(1.30)x to model the number of mold spores per week. what does the 1.30 represent? how many mold spores are there after 4 weeks? round your answer to the nearest whole number. 1.30 represents the number of mold spores marco had at the beginning of the study; 985 mold spores 1.30 represents the number of mold spores grown in a given week; 448 mold spores 1.30 represents the 30% rate of weekly growth; 345 mold spores 1.30 represents the 30% rate of weekly growth; 985 mold spores