Idk what he answer is pls help

Triangle abc is reflected over the line y=x triangle abc has points (-6,-,-1) and (-5,-6) what is the c coordinate

(a) compute the maclaurin polynomial m2(x) for f(x) = cos x. (b) use the polynomial of part (a) to estimate cos π 12. (c) use a calculator to compute the error made using the estimate from part (b) for the value of cos π 12. remember that the error is defined to be the absolute value of the difference between the true value and the estimate.

Combine like terms to make a simpler expression 3z+z