Cos2a= 2cos^2a-1 for all values of a true or false?
2 answers:
For the solution/answer of this question, we will use the double angle formula which can be derived as follows:
Now, the above expression can be simplified to:
(Because
)
Therefore, we can further simplify it to:
which is the proof which is required.
Thus, we have proved that:
Thus, this equality is true for all values of a.
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Answer:
See explanation below for further details.
Step-by-step explanation:
A rational consist of two real numbers such that:
If c is a polynomial with a certain grade, then, both the numerator and the denominator must be also polynomials and the grade of the numerator must be greater than denominator.
If c is linear function, that is, a first order polynomial, then a must be a (n+1)-th polynomial and b must be a n-th polynomial.
Example:
If and
, then:
If c is a quadratic function, that is, a second order polynomial, then a must be a (n+1)-th polynomial and b must be a n-th polynomial.
Example
If and
, then:
But if c is an exponential, both the numerator and the denominator must be therefore exponential function and grade of each exponential function must different to the other.
Example
If and
, then:
Otherwise, c would be equal to a constant function, that is, a polynomial with a grade 0.
If and
, then:
Example
It is worth to add that exponential functions can be a linear combination of single exponential function, similar to polynomials.
Example