Answer:
see explanation
Step-by-step explanation:
Consider the left side
A +
A - 2cos²Asin²A ← is the expansion of
= (cos²A - sin²A)²
Substitute sin²A = 1 - cos²A
= (cos²A - (1 - cos²A) )²
= (cos²A - 1 + cos²A)²
= (2cos²A - 1 )²
= right side , then proven
Answer:
48
Step-by-step explanation:
48
Let the tens digit be x.
Hence, the units digit will be 2x
Number =10×(x)+(2x)=12x
When 36 is added to the number, the new number formed =12x+36
As the digits are reversed, we can also write the new number as 10×(2x)+x=21x
Hence,
12x+36=10×(2x)+x
⇒12x+36=21x
⇒21x−12x=36
⇒9x=36
⇒x=4
Hence, the original number =12x=12×4=48
Answer:
the is 51
Step-by-step explanation:
24 + 32 + -5 is 51