Tangents (Leaving Cert Mathematics): Flashcards

📚Flashcards
Tangents
Sign up to keep revising.Create a free account to study more flashcards and track your progress.

Practise the cards

10 cards from this deck

Show

Number of points where tangent touches circle

Exactly one point

Name of point where tangent meets circle

Point of contact

Relationship between tangent and radius at contact

Perpendicular

Number of tangents at a point on circumference

Only one (unique)

Number of tangents from external point

Two tangents

Lengths of two tangents from external point

Equal

Tangent equation at (x1,y1)(x_1, y_1) on x2+y2=r2x^2 + y^2 = r^2

xx1+yy1=r2xx_1 + yy_1 = r^2

Tangent at (x1,y1)(x_1, y_1) on (x−h)2+(y−k)2=r2(x-h)^2 + (y-k)^2 = r^2

(x1−h)(x−h)+(y1−k)(y−k)=r2(x_1-h)(x-h) + (y_1-k)(y-k) = r^2

Common tangents between two circles

Possible, internally or externally

Tangent to x2+y2=25x^2 + y^2 = 25 at (3,4)(3, 4)

3x+4y=253x + 4y = 25

Join 100,000+ Leaving Cert students studying Flashcards with us.

Select your subjects, and get access to A+ resources today.