Question

how to solve trigonometry in easy way

Answer 1

Answer:

here’s what an identity proof is: it’s a list of expressions that are exactly the same as one side of the identity. Eventually, you come up with one that’s exactly the same as the other side of the identity. For example: if you had to prove that sec2(x)–tan2(x)≡1, you could start by saying:

Step-by-step explanation:

“Well, I know sec2(x) is the same as 1cos2(x), and tan2(x) is the same as sin2(x)cos2(x), so I can write something equivalent to the left hand side”:

1cos2(x)–sin2(x)cos2(x)

“Oh! I have a pair of fractions with the same denominator. Let me combine them to get another thing that’s the same”:

1–sin2(x)cos2(x)

“That’s looking simpler. I know the identity for linking sin2(x) and cos2(x), so I can replace that top with cos2(x)…”

cos2(x)cos2(x)

“And that’s clearly 1!”