1.The total surface area of a right circular cone has
increased by 44%.Find the percentage increases in
A)base radius
B)volume
2.If the surface area of aa spherical balloon increases
by 21%,find the percentage increases in
a)radius
b)volume
其實我學左咁耐數學,唔知點解呢個竟然係一個最難的一part,
除左ratio比較之外,個d咩搵出decreasing,increasing in radius等,
要寫勁多條式,雖然都係用返A1/A2=(r1/r2)^2,V1/V2=(r1/r2)^3既
formula,但減黎減去,加黎加去,好煩惱,唔通要死背,有什麼方法
可以掌握呢一課呢?(星期一exam數學)