the correct answer should be (b) 6 is extraneous.
If you look at the second row of the solution you see (x-6) as a factor in one of the denominators. That's a problem: if 6 were a solution this denominator would become 0. But denominators being 0 is bad (undefined), so while 6 comes out of the algebraic manipulation as a solution, it is invalid, or extraneous.
-3 is a fine solution.
9514 1404 393
Answer:
(0, π/4] ∪ (π, 5π/4]
Step-by-step explanation:
Multiplying by 2 gives ...
cot(x) ≥ 1
The cotangent function decreases from ∞ to 1 in the domain (0, π/4], and again in the domain (π, 5π/4]. The solution is the union of these two intervals.
x ∈ (0, π/4] ∪ (π, 5π/4]
_____
(a, b] is interval notation for a < x ≤ b
Answer:
( -1 , 1 )
Step-by-step explanation:
(x1,y1) = (5,9)
(x2,y2) = (-7,-7)
=(-7+5/2 , -7+9/2)
= (-1,1)