Aylanish figuralari

AB = 2AD = 2

demak, konus sirti S_k = 9π.

Bundan, = .

Javob: .
14 – masala. Silindrning yasovchisiga tik bo`lgan kesimning yuzi Q ga, o`q kesimining yuzi esa S ga teng. Bu silindrning to`la sirtini va hajmini toping.

Y

echilishi:

Masala shartiga ko`ra, S_ABCD= S, S_asos = Q

Bundan quyidagi tengliklarni yozish mumkin:

S = AB · AD = 2AO · AD,

Q = π · AO².

Bizga ma`lumki, silindr to`la sirti

S_t.c. = S_yon +2S_asos . Yuqori dagi tengliklardan

AO= , AD = S/2 .

Bulardan,

S_t.c = 2π · AO · AD + 2π · AO² = πS + 2Q.

Ma`lumki silindr hajmi V = π · AO² · AD ekanligidan,

V = S_t.c = πS + 2Q.

Javob: V == .

15 – masala. Konus yon sirtining yuzi asosining yuzidan ikki marta katta. Uning o`q kesimining yuzi Q ga teng. Konusning hajmini toping.