Verify The Identity Cos(x)+Sin(x)Tan(x)=Sec(x) Can someone please help explain to me how to verify an identity?
try drawing a triangle and label the ratios and go from there....
Ok.. I guess I'm confused by what ratios? No numbers were given. I know you probably would start with the left side of this equation (maybe divide each side by tan(x)?)
use this, and create your ratios...Example Sin=b/c http://3.bp.blogspot.com/_kjNvt_oqTsE/TORcXMO_H6I/AAAAAAAAACo/CbLIh4wjhaI/s1600/Image289.gif
put it in those terms and it should be easier for you to prove...
Proving a proof cannot be done using what is given, it must be changed to new terms...Just like the definition of a word can't include the word....
does it matter where I put each term?
put them in the order of the identity...So, Cosx becomes (a/c) etc...
oh ok...
so I have cosx=a/c sinx=b/c and tanx= c/?
the tangent is what? Its the opposite side/adjacent side... (b/a)
So...(a/c)+(b/c)(b/a) and solve...
OHHH ok! and I want it to equal secx which is equal to what? a/b?
OHHH ok! and I want it to equal secx which is equal to what? a/b?
i have confused you, and I'm sorry...You need to see that Tangent equals (sin/cos) and make that substitution.
Once you see that, then the fractions become easier to work, because they are impossible to work without that substitution.
ok so i understand that now...
Completely ignore the answer Secant side of the equation, and solve the fractional problem...and you'll determine what secant is in terms of fractions, which is what they want....
So, basically, this... sin x tan x + cos x = sin x (sin x / cos x) + cos x = ( sin^2(x) / cos x ) + cos x = [ sin^2(x) + cos^2(x) ] / cos x = 1 / cos x = sec x
Alright so I was close on my paper... I think I just mixed up the terms. Therefore this is an identity. Thank you!
Ok one more Question...does theta basically resemble the x in the previous problem?
Join our real-time social learning platform and learn together with your friends!