Answer: Only the second sequence is arithmetic.
Work:
An arithmetic sequence is a sequence in which there is a common value added or subtracted between each term in the sequence.
The first option, -2, 4, -6, 8,... is not arithmetic because the terms switch back and forth between positive and negative signs meaning that there is no common value that can be added between each term.
The second option, -8, -6, -4, -2,... is arithmetic because there is a common difference between each term which is +2.
The third option, 2, 4, 8, 16,... is not arithmetic but is, in fact, geometric. There is no common value that is added or subtracted between each term.
Answer:
25
Step-by-step explanation:
Check the picture below.
we know that AL is an angle bisector, so the angle at A gets cuts into two equal halves, we also know the angle at B is 30°, so the triangle ABC is really a 30-60-90 triangle, meaning the angle at A is really a 60° angle, cut in two halves gives us 30° and 30° as you see in the picture.
if the angles at A and B, inside the triangle ABL, are equal, twin angles are only made in an isosceles by twin sides, that means that AL = BL.
Looking at the triangle ALC, we can see is also another 30-60-90 triangle, and we can just use the 30-60-90 rule to get x=CL.
(a) Yes all six trig functions exist for this point in quadrant III. The only time you'll run into problems is when either x = 0 or y = 0, due to division by zero errors. For instance, if x = 0, then tan(t) = sin(t)/cos(t) will have cos(t) = 0, as x = cos(t). you cannot have zero in the denominator. Since neither coordinate is zero, we don't have such problems.
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(b) The following functions are positive in quadrant III:
tangent, cotangent
The following functions are negative in quadrant III
cosine, sine, secant, cosecant
A short explanation is that x = cos(t) and y = sin(t). The x and y coordinates are negative in quadrant III, so both sine and cosine are negative. Their reciprocal functions secant and cosecant are negative here as well. Combining sine and cosine to get tan = sin/cos, we see that the negatives cancel which is why tangent is positive here. Cotangent is also positive for similar reasons.
