Question

18. Find the distance of a point P(x,y) form the origin.
19.Find sinA if CosA 12/13​

Answer 1

18.

$\sqrt{ {x }^{2} + {y}^{2} }$

19. 5/12

Step-by-step explanation:

18. the distance between (x,y) and (x,0) is y units

the distance between (x,y) and (0,y) is x units

there it forms an right angled triangle

by pythagoras theorem

hypotenuse² = sum of squares of other two sides

therefore, distance between origin and point P(x,y)

is

$\sqrt{ {x }^{2} + {y}^{2} }$

19. Cos A = 12/13

Cos(A) = opposite side/hypotenuse

therefore two sides of the triangle are 12 units and 13 units

by pythagoras theorem

remaining side of triangle is 5 units

therefore SinA = adjacent side/hypotenuse

SinA = 5/12

Answer 2

$\huge{ \boxed{ \mathcal \pink{19. \: solution}}}$

$=> sin \: a = cos(90 - a)$

$=> sin \: a = ( \frac{90}{1} - \frac{12}{13} )$

$=> sin \: a = ( \frac{900 - 12}{13} )$

$=> sin \: a = ( \frac{988}{13})$

$=> sin \: a = 76$

$\large\mathbb \purple{hope \: it \: help \: you}$