Identifying an Error
A student estimated the sum
7.95 + 8.11 + 78.5 +8.05 + 79.4 +0.815 as:
All the numbers begin with a 7 or 8, so use cluster
estimation
8-8-80-8-80-0.8 = 184.8
Explain why this reasoning is not accurate.

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

Ineed if you could explain and give me the answer you! this needs done

Mary beth used the mapping rule to find the coordinates of a point that had been rotated 90° counterclockwise around the origin. examine the steps to determine whether she made an error. m (3, –6) is rotated 90° counterclockwise. (x, y) → (–y, x) 1. switch the x- and y-coordinates: (6, –3) 2. multiply the new x-coordinate by –1: (6(–1), –3) 3. simplify: (–6, –3) .