Answer:
Option A is correct
Difference of squares identity should be used to prove 49-4 =45
Step-by-step explanation:
Prove that : 49 - 4 = 45
Polynomial identities are just equations that are true, but identities are particularly useful for showing the relationship between two apparently unrelated expressions.
Difference of the squares identity:

Take LHS
49 - 4
We can write 49 as
and 4 as
.
then;

Now, use the difference of square identity;
here a =7 and b = 2

or
= RHS proved!
therefore, the difference of square polynomial identity should be used to prove that 49-4 =45
Answer:
10 1/4
Step-by-step explanation:
Sean has scored a score of 65% on his spelling test
Sec(x/2) = 1/cos(x/2)
sec(x/2)=cos(x/2) ----> cos^2(x/2)=1 ---> cos(x/2) = -1 and cos(x/2) = 1
Cos(x/2)=1 --- > x/2 = 0, only. x = 0;
cos(x/2)=-1 ----> x/2 = pi -> x = 2pi. But the statement says [0,2pi), so 2pi can not be chosen.
Only x = 0.
In fact, your equation is equivalent to sec(x)=cos(x), for x in [ 0, pi), so yes, only x = 0 .