Answer:
First option: cos(θ + φ) = -117/125
Step-by-step explanation:
Recall that cos(θ + φ) = cos(θ)cos(φ) - sin(θ)sin(φ)
If sin(θ) = -3/5 in Quadrant III, then cos(θ) = -4/5.
Since tan(φ) = sin(φ)/cos(φ), then sin(φ) = -7/25 and cos(φ) = 24/25 in Quadrant II.
Therefore:
cos(θ + φ) = cos(θ)cos(φ) - sin(θ)sin(φ)
cos(θ + φ) = (-4/5)(24/25) - (-3/5)(-7/25)
cos(θ + φ) = (-96/125) - (21/125)
cos(θ + φ) = -96/125 - 21/125
cos(θ + φ) = -117/125
Answer: A.
Step-by-step explanation:
Sum of the number and its of inverse equals 0.
Answer:
1/ 3
Step-by-step explanation:
If each of the cards is turned over, the probability of picking up a card of one type P(E) becomes equal to:
=> P(E) = number of cards of the required type/ total number of cards
● Total number of spades( ♤ ) = 3
{the queen, one ace and the nine are all spades}
● Total number of cards = 6
Probability of drawing a spade= 3/ 6
= 1/ 2
● Total number of "7" = 1
● Total number of cards = 6
Probability of drawing a 7
= 1/ 6
Now, what's asked is the difference in the probabilities of drawing a spade and a seven.
= 1/ 2 - 1/ 6
= 3/ 6 - 1/ 6
= 2/ 6
= 1/ 3
Hence, 1/ 3 of a greater chance of drawing a spade over a 7.
Answer:
(-1)ⁿ(3)ⁿ/10
Step-by-step explanation:
The first term a = 0.3, the second term, ar = 0.9. The common ratio r = ar/a = 0.9/-0.3 = -3.
From the general term of a geometric series,
U = arⁿ⁻¹
= (0.3)(-3)ⁿ⁻¹
= (3/10)(-3)ⁿ⁻¹
= (-1)ⁿ⁻¹(3)(3)ⁿ⁻¹/10
= (-1)ⁿ(3)ⁿ/10
