Answer:
A. -2sin(x)sin(0.4x)
Step-by-step explanation:
At x=0, the given expression evaluates to zero.
For x near zero, the given expression is slightly negative. You know this because cos(1.4x) decreases faster than cos(0.6x), so their difference will be negative.
Of the answer choices, you can eliminate C and D because they are not zero at x=0. You can eliminate choice B, because it is positive for values of x near zero. The only viable choice is A:
-2sin(x)sin(0.4x)
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Of course, a graphing calculator can help you figure this out. See the attachment. The given expression is plotted using a solid red line; the answer choice A is plotted using blue dots.
Answer: OPTION C
Step-by-step explanation:
Remember that:
And the Product of powers property establishes that:
Rewrite the expression:
Descompose 18 and 32 into their prime factors:
Substitute into the expression, then:
Finally,simplifying, you get:
Answer:
The vertex (h,k) is (-4,-7).
Step-by-step explanation:
I assume you are looking for the vertex .
The vertex form of a quadratic is where the vertex is (h,k) and a tells us if the parabola is open down (if a<0) or up (if a>0). a also tells us if it is stretched or compressed.
Anyways if you compare to
, you should see that
.
So the vertex (h,k) is (-4,-7).
Hence, the sum of a 7-term geometric series is:
-32766.
<h3><u>Step-by-step explanation:</u></h3>We have to find the sum of a 7-term geometric series (i.e. n=7) if the first term(a) is -6, the last term is -24,576, and the common ratio(r) is 4.
We know that the sum of the 7-term geometric series is given as:
On putting the value of a,n and r in the given formula we have:
Hence, the sum of a 7-term geometric series is:
-32766.