Math, asked by arjun8839, 1 year ago

sina=3/5 cosb=12/13 find value of sin(a+b)

Answers

Answered by PrayagKumar

$<b>HEY THERE!$

GIVEN :- sina=3/5 cosb=12/13.

TO SOLVE :- value of sin(a+b)

CONSTRUCTION :- First given is the value of sina so we will find the value of cosa

So sina = 3/5 => Perpendicular/ hypoteneus

So now using pithogorus trick Base = 4
now cosa = Base / hypoteneus
cosa= 4/5

Now given is the value of cosb so we will find sinb
So cosb=>12/13 => Base / hypoteneus
So using pithogorus trick Perpendicular = 5

now sinb => Perpendicular / hypoteneus => 5/13

SOLUTION :- As we know
sin(a+b) = sina cosb - cosa sinb

So now put the values of sina, cosa , sinb and cosb in the formula.

sin(a+b) = sina cosb - cosa sinb
=>sin(a+b) = 3/5 × 12/13 - 4/5 × 5/13
=> sin(a+b) = 36/65 - 4/13
=> sin(a+b) = (36 - 20 )/65
=> sin(a+b) = 16 / 65

HOPE IT HELPED YOU.

arjun8839: sir this is wrong formula of sin(a+b) you have put

PrayagKumar: no it is right

PrayagKumar: hence above is wrong

arjun8839: and the value ofsina is 3/5 you put 3/4

PrayagKumar: ohhh sry

PrayagKumar: now i did and thnka for telling my Mistake

Answered by ramdhakal12

Answer:

<b>HEYTHERE!

GIVEN :- sina=3/5 cosb=12/13.

TO SOLVE :- value of sin(a+b)

CONSTRUCTION :- First given is the value of sina so we will find the value of cosa

So sina = 3/5 => Perpendicular/ hypoteneus

So now using pithogorus trick Base = 4

now cosa = Base / hypoteneus

cosa= 4/5

Now given is the value of cosb so we will find sinb

So cosb=>12/13 => Base / hypoteneus

So using pithogorus trick Perpendicular = 5

now sinb => Perpendicular / hypoteneus => 5/13

SOLUTION :- As we know

sin(a+b) = sina cosb - cosa sinb

So now put the values of sina, cosa , sinb and cosb in the formula.

sin(a+b) = sina cosb - cosa sinb

=>sin(a+b) = 3/5 × 12/13 - 4/5 × 5/13

=> sin(a+b) = 36/65 - 4/13

=> sin(a+b) = (36 - 20 )/65

=> sin(a+b) = 16 / 65

HOPE IT HELPED YOU.

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