Answer:dfdasfsdafdasfdasfdasfdasfdsafdasfdasfdasfdasfdasfdsafasfdas
Step-by-step explanation:dsgdasjghdasfkjhdasfjhasdfjdaskfhasfkjdhasfkljhdasfkjhdskjahfdkjsahfkljdashfkjdsahfkjdashfkjdhsafdhsfkjdhsfkljdhfkjdhasfkljdashfkljdsahfkjdshfkljds
Answer:
tan²x + 1 = sec²x is identity
Step-by-step explanation:
* Lets explain how to find this identity
∵ sin²x + cos²x = 1 ⇒ identity
- Divide both sides by cos²x
∵ sin x ÷ cos x = tan x
∴ sin²x ÷ cos²x = tan²x
- Lets find the second term
∵ cos²x ÷ cos²x = 1
- Remember that the inverse of cos x is sec x
∵ sec x = 1/cos x
∴ sec²x = 1/cos²x
- Lets write the equation
∴ tan²x + 1 = 1/cos²x
∵ 1/cos²x = sec²x
∴ than²x + 1 = sec²x
- So we use the first identity sin²x + cos²x = 1 to prove that
tan²x + 1 = sec²x
∴ tan²x + 1 = sec²x is identity
Answer:
b = 9
Step-by-step explanation:
Using Pythagoras' identity in the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
b² + 12² = 15²
b² + 144 = 225 ( subtract 144 from both sides )
b² = 81 ( take the square root of both sides )
b = 
= 9
Answer:
y = 3
Step-by-step explanation:
2x-3y = -5 --------- (1)
y = 2+x ------- (2)
substitute (2) into (1)
2x-3y = -5
2x-3( 2+x ) = -5
2x-6-x = -5
2x-x = -5+6
x = 1
substitute x = 1 into (2)
y = 2+x
y = 2+1
y = 3
