Step-by-step explanation:
To prove :
( 1 - sin x ) ( 1 + sin x ) = sec² x
LHS : -
( 1 - sin x ) ( 1 + sin x )
Formula / Identity : -
( a - b ) ( a + b ) = a² - b²
Here,
a = 1
b = sin x
( 1 - sin x ) ( 1 + sin x )
= 1 - sin² x
Identify : -
sin² θ + cos² θ = 1
cos² θ = 1 - sin² θ
Similarly,
1 - sin² x
= cos² x
= RHS
Hence verified.
Answer:
A
Step-by-step explanation:
Iwis
15 / 330 = 20 / x...15 gal. to 330 miles = 20 gal to x miles
cross multiply because this is a proportion
(15)(x) = (20)(330)
15x = 6600
x = 6600/15
x = 440 <=== 20 gallons will take u 440 miles
Subtract g add 1 divide by 2a
The answer is 19.4
Most of the time when you try to find a missing length of a right triangle you use Pythagorean theorem. Pythagorean theorem is A squared plus B squared equals C squared. C squared is always going to be the longest length/diagonal line otherwise known as your hypotenuse. In this case the ladder is the hypotenuse. So instead of adding five squared +20 squared you’re going to square 20 and then subtract five squared to get the missing length which would be B squared and then you have to find the square root of B squared. So 20 squared is 4000. 5squared is 25 400-25 = 375 square root of 375 is about 19.4.