It'd be easier to do #18 if y ou were to break it up:
14* (first term + 14th term)
Sum from n=1 to 14 of n = S = ---------------------------------
14 2
14(1+14)
= ---------------- = 7(15) = 105
2
The sum of twice that is 210. The sum of "1 from n=1 to n=14" is just 14.
The final sum is 210 + 14 = 224 (answer)
Circumference of a circle = 2πr
Circumference of the whole circle= 2π(30) = 60π
360 - 90 = 270
Length XPY = 270/360 x 60π = 45π
Answer: 45π m
Answer:
The letter "i" is used to signify that a number is an imaginary number.
Step-by-step explanation:
An imaginary number is one that gives a negative result when squared. This differs from when you square real numbers where you always get a positive result. For example:
i = √-1
Imaginary numbers can be especially useful when trying to find the square root of a real negative number such as -16. Normally we cannot find the square root of -16 but through the use of imaginary numbers we can:
√-16 = 4i
~Hope this helps!~
Is there a picture of the ramp?
