In planning for tightening 500 bolts, it was measured that the bolt head twists off at a mean torque of 20N-m with a standard deviation of 1 N-m. If only one failure can be accepted in this group, what is the highest mean torque the wrench should be set at if the standard deviation of the wrench is 1.5N-m

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.

this answer is !

is there a question here?

step-by-step explanation: