Word	Excel
ax²+2kx+c=0 D₁=k²−ac x=(−k±√D͞₁)/a	ax^2+2kx+c=0 D(1)=k^2-ac x=(-k(+-)sqrt(D(1)))/a
△ABC, ∠C=90°, BC=a, AC=b, AB=c, CO=h, AO=b₍, BO=a₍: b₍+a₍=c △AOC∼△BOC∼△ABC b=√b͞₍͞c h=√a͞₍͞b͞₍	triangle(ABC), angle(C)=90*degree(), BC=a, AC=b, AB=c, CO=h, AO=b(c), BO=a(c): b(c)+a(c)=c triangle(AOC)=similar(triangle(BOC))=similar(triangle(ABC)) b=sqrt(b(c)c) h=sqrt(b(c)a(c))
Aₙᵏ=n!/(n−k)!	A(n;k)=n!/(n-k)!
Cₙᵏ=n!/(k!(n−k)!)	C(n;k)=n!/(k!(n-k)!)
H≤G≤x̄	H(<=)G(<=)average(x)
△ABC, ∠C=90°: sinA=cosB=BC/AB cosA=sinB=AC/AB tgA=ctgB=BC/AC=sinA/cosA=cosB/sinB ctgA=tgB=AC/BC=cosA/sinA=sinB/cosB sin²A+cos²A=sin²B+cos²B=1	triangle(ABC), angle(C)=90*degree(): sin(A)=cos(B)=BC/AB cos(A)=sin(B)=AC/AB tg(A)=ctg(B)=BC/AC=sin(A)/cos(A)=cos(A)/sin(B) ctg(A)=tg(B)=AC/BC=cos(A)/sin(A)=sin(B)/cos(B) sin(A)^2+cos(A)^2=sin(B)^2+cos(B)^2=1
CIRCUMFERENCE WITH CENTER O, RADIUS OA AND TANGENT p: p⊥OA	CIRCUMFERENCE WITH CENTER O, RADIUS OA AND TANGENT p: p=perpend(OA)
CIRCUMFERENCE WITH CENTER O, RADII OB AND OC, AND TANGENTS AB AND AC: AB=AC ∠1=∠2	CIRCUMFERENCE WITH CENTER O, RADII OB AND OC, AND TANGENTS AB AND AC: AB=AC angle(1)=angle(2)
CIRCUMFERENCE WITH CENTER O, RADII OA AND OB, AND ARC ALB: ⌒ALB=∠AOB	CIRCUMFERENCE WITH CENTER O, RADII OA AND OB, AND ARC ALB: arc(ALB)=angle(AOB)
CIRCUMFERENCE WITH CENTER O, CHORDS AB AND BC, AND ARC ALC: ⌒ALC=2×∠ABC	CIRCUMFERENCE WITH CENTER O, CHORDS AB AND BC, AND ARC ALC: arc(ALC)=2*angle(ABC)
CIRCUMFERENCE WITH CENTER O, TANGENT AB, SECANT AN AND CHORD MN: AB²=AN×AM	CIRCUMFERENCE WITH CENTER O, TANGENT AB, SECANT AN AND CHORD MN: AB^2=AN*AM
CIRCUMFERENCE WITH CENTER O, TANGENT AB, CHORD AC AND ARC ALC: ⌒ALC=2×∠BAC	CIRCUMFERENCE WITH CENTER O, TANGENT AB, CHORD AC AND ARC ALC: arc(ALC)=2*angle(BAC)
a⁻ⁿ=1/aⁿ	a^(-n)=1/a^n
∠BAC, ∠BAK=∠CAK, KM⊥AB, KN⊥AC: MK=NK	angle(BAC), angle(BAK)=angle(CAK), KM=perpend(AB), KN=perpend(AC): MK=NK
AB⊥MN, AN=BN: AC=BC	AB=perpend(MN), AN=BN: AC=BC
△ABC WITH INSCRIBED CIRCUMFERENCE WITH CENTER O AND RADIUS r, p=P/2: S=pr	triangle(ABC) WITH INSCRIBED CIRCUMFERENCE WITH CENTER O AND RADIUS r, p=P/2: S=pr
△ABC, A̅B⃗=a⃗, B̅C⃗=b⃗: a⃗+b⃗=A̅B⃗+B̅C⃗=A̅C⃗	triangle(ABC), vector(AB)=vector(a), vector(BC)=vector(b): vector(a)+vector(b)=vector(AB)+vector(BC)=vector(AC)
PARALLELOGRAM ABCD, A̅B⃗=C̅D⃗=a⃗, B̅C⃗=A̅D⃗=b⃗: a⃗+b⃗=b⃗+a⃗=A̅C⃗	PARALLELOGRAM ABCD, vector(AB)=vector(CD)=vector(a), vector(BC)=vector(AD)=vector(b): vector(a)+vector(b)=vector(b)+vector(a)=vector(AC)
△ABC, A̅B⃗=a⃗, A̅C⃗=b⃗: a⃗−b⃗=C̅B⃗	triangle(ABC), vector(AB)=vector(a), vector(AC)=vector(b): vector(a)-vector(b)=vector(CB)
S=ab×sinC/2	S=ab*sin(C)/2
a/sinA=b/sinB=c/sinC	a/sin(A)=b/sin(B)=c/sin(C)
a²=b²+c²−2bc×cosA	a^2=b^2+c^2-2bc*cos(A)
a⃗b⃗=|a⃗||b⃗|cosA=x₁x₂+y₁y₂	vector(a)*vector(b)=|vector(a)|*|vector(b)|*cos(A)=x(1)x(2)+y(1)y(2)
aₙ=2R×sin(180°/n)	a(n)=2R*sin(180*degree()/n)
r=R×cos(180°/n)	r=R*cos(180*degree()/n)
l=πrα/180	l=pi()*r*alpha()/180
S=πr²α/360	S=pi()*r^2*alpha()/360
Sₙ=(2a₁+d(n−1))n/2	S(n)=(2a(1)+d(n-1))n/2
Sₙ=b₁(qⁿ−1)/(q−1)	S(n)=b(1)(q^n-1)/(q-1)