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Mathematics 11 Online
snowflake0531:

@AZ hehe

AZ:

hmm let's just foil and see what we're dealing with \( (a+b)(c+d) = ac + ad + bc + bd\)

snowflake0531:

sinxtanx + sinxcotx + cosxtanx + cosxcotx

AZ:

okay mhmm now let's just re-write those all in terms of sin and cos and then simplify remember tan(x) = sin(x) / cos(x) cot(x) = 1/ tan(x) = cos(x) / sin(x)

AZ:

and once you get that you'll find that you can add the fractions that have the same denominators and then you can use identities to simplify the numerators and ta-da

snowflake0531:

so I got sinx + cosx + sinx tanx + cosx cotx

snowflake0531:

so then sinx + cosx + sinx(sinx/cosx) + cosx(cosx/sinx)

snowflake0531:

then, i'm confused ?_?

snowflake0531:

sinx + cosx + sinx(sinx^2/sinxcosx) + cosx(cosx^2/sinxcosx)

snowflake0531:

yep, i'm definitely still so confused

AZ:

\(\color{#0cbb34}{\text{Originally Posted by}}\) @snowflake0531 sinxtanx + sinxcotx + cosxtanx + cosxcotx \(\color{#0cbb34}{\text{End of Quote}}\) the one you said more recently is incorrect, I'm not sure where you got rid of some terms but let's start form here

snowflake0531:

sinx(sinx/cosx) + sinx(cosx/sinx) + cosx(sinx/cosx) + cos(cosx/sinx)

AZ:

ohhh I see now

snowflake0531:

am i still wrong? lol

AZ:

no no, you're on the right track I was wrong with what I had said earlier so this is correct \(\color{#0cbb34}{\text{Originally Posted by}}\) @snowflake0531 so then sinx + cosx + sinx(sinx/cosx) + cosx(cosx/sinx) \(\color{#0cbb34}{\text{End of Quote}}\)

snowflake0531:

kk

AZ:

once you're here now, you multiply the sin and cos into the parenthesis respectively remember it's like a*(b/c) = (ab) / c

AZ:

whatever you had done afterwards like the following is all wrong because you multiplied both the numerator and denominator \(\color{#0cbb34}{\text{Originally Posted by}}\) @snowflake0531 sinx + cosx + sinx(sinx^2/sinxcosx) + cosx(cosx^2/sinxcosx) \(\color{#0cbb34}{\text{End of Quote}}\) big no no

snowflake0531:

So (sin^2 x)/cosx + cos^2 x)/sinx + sinx + cosx

AZ:

Good! Now remember the identities sin^2 x = 1 - cos^2 x and cos^2 x = 1 - sin^2 x plug both of those respective ones in place of sin^2 x and cos^2 x and simplify the fractions remember \(\dfrac{a-b}{c} = \dfrac{a}{c} - \dfrac{b}{c}\)

AZ:

those two identities are based off of sin^2(x) + cos^2(x) = 1

snowflake0531:

1/cosx - cosx^2/cosx = secant x - cosx 1/sinx - sin^2x/sinx = cosecant x - sinx sec x - cosx + cscx - sinx

snowflake0531:

and hten plus the sinx and cosx

AZ:

and you'll see that the sin and cos will cancel out leaving you with the RHS

snowflake0531:

ohhhhhhh, kay, i finished writing it thankssssssssssssssssssss xdxd

AZ:

no problemo!!

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