What are the options ???
Step-by-step explanation:
Step-by-step explanation:
If the two chords are congruent, then they must be equidistant from the centre of the circle.
Answer: <u><em>D) They must be perpendicular</em></u>
A is rejected because the chord might not pass through the center of the circle.
B is rejected because the chords are not obligated to be parallel.
C is rejected because it is not compulsory for the chords to be perpendicular.
Answer: C
Step-by-step explanation:
To find the surface area of a cone, you use the formula 
. Since we are already given the height and radius, all we have to do is plug in the values and solve.
[solve inside of square root]
[parenthesis]
[multiply]
Therefore, the closest answer is C.
A good place to start is to set 
to y. That would mean we are looking for 
to be an integer. Clearly, 
, because if y were greater the part under the radical would be a negative, making the radical an imaginary number, not an integer. Also note that since 
is a radical, it only outputs values from ![[0,\infty]](https://tex.z-dn.net/?f=%20%5B0%2C%5Cinfty%5D%20)
, which means y is on the closed interval: ![[0,120]](https://tex.z-dn.net/?f=%20%5B0%2C120%5D%20)
.
With that, we don't really have to consider y anymore, since we know the interval that is on.
Now, we don't even have to find the x values. Note that only 11 perfect squares lie on the interval , which means there are at most 11 numbers that x can be which make the radical an integer. All of the perfect squares are easily constructed. We can say that if k is an arbitrary integer between 0 and 11 then:
Which is strictly positive so we know for sure that all 11 numbers on the closed interval will yield a valid x that makes the radical an integer.
