The sum of the first n consecutive even numbers can be found using S=n2+n, where n≥2. What is the value of n when the sum is 42? Question 8 options:

7

14

6

3

Step-by-step explanation:

Given

Substitute and solve for n:

Correct option is C

C. 6

Step-by-step explanation:

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92