Answer:
Step-by-step explanation:
Given 
, start by squaring both sides to work towards isolating 
:
Recall 
and 
:
Isolate the radical:
Square both sides:
Expand using FOIL and 
:
Move everything to one side to get a quadratic:
Solving using the quadratic formula:
A quadratic in 
has real solutions 
. In 
, assign values:
Solving yields:
Only works when plugged in the original equation. Therefore, 
is extraneous and the only solution is 
Answer:
Incident ray, the reflection ray and the normal to thereflection surface at the point of the incidence lie in the same plane
Answer:
she only needs to work ten hours
Explanation: if you subtract 45 from 115 you well end up with 70 a and if you work for ten hours 7 ×10=70 so you would have enough.
Answer:
P(X<1200) is 0.8212
Step-by-step explanation:
Test statistic (z) = (X - mean)/sd
X is score of a tester = 1200
mean = 1497
sd = 322
z = (1200 - 1497)/322 = -297/322 = -0.92
The cumulative area of the test statistic is the probability that X<1200. The cumulative area is 0.8212.
Therefore, P(X<1200) = 0.8212
